Fit – {Grapefruit Poppy Seed Cupcakes with Strawberry Rhubarb Jam and Cream Cheese Swiss Meringue Buttercream}

My budget-friendly, no-name, strap-covered, lace-up, too-small work shoes have finally worn in. Over the past month, I’ve gotten used their song over the wooden floors of the office and become accustomed to the funky way they make me walk up and down stairs.

I’ve discovered the ever-flowing source of coffee in the back room and – thanks to the help of our office assistant, C – located its neatly organized accompaniments within the nearby drawers and cabinets. Today I even learned how to make a decent pot under coworker N’s instruction.

So, have you guessed? I got the internship! I apologize for my absence in recent weeks, but work, school and friends have been keeping me busy – and pleasantly so. I think, however, that things will be easing up now and I should be able to resume my regular posting schedule from this point forward. Huzzah!

But, back to work:

The office is so friendly and relaxed that I don’t feel like I’m “at work” while I’m there. It’s more like I’m hanging out with friends who just happen to be collaborating on cool projects 24/7. Does that sound weird? I can’t decide. Either way, it’s amazing and I plan to enjoy every second of it.

I credit much of my comfort to the presence of humor in the office – which I appreciate more than I’m capable of expressing – and the fact that everyone is so helpful and accepting and nice and witty and… Wow. I sound like a suck up. I swear that’s not what I’m going for, but it’s difficult to share the details of this experience without feeling like I’m coming off that way!

I’m learning so much from everyone and finally seeing the ways that things I’ve studied in class can be applied to life. I was even able to help analyze the results of a focus group in the same week that we went over them in one of my classes. Maybe it means nothing to you, but it was incredibly exciting for me! So much so that I emailed my boss at 9:48 on a Saturday night to let her know how giddy I was that I had, at that moment, just finished reading about focus groups in my textbook.

You know, because cool kids read market research textbooks on Saturday nights.

I certainly haven’t learned everything there is to know and I ask lots of questions (computer ones, lately. I’m a PC in an overwhelmingly Mac world), but I’m settling in – and I love it!

But, before I get back to the stack of textbooks lovingly calling out to me from across my uncomfortably disheveled bedroom (can’t wait to cleannnnn), I want to thank all of you for sticking with me, both when I am and am not here! Also, thanks for your continued encouragement – this blog was a large part of the reason I got the internship, and I couldn’t have done it without your help!

All the best,

Grapefruit Poppy Seed Cupcakes with Strawberry Rhubarb Jam and Vanilla Cream Cheese Swiss Meringue Buttercream
I took these to work today and they were a hit! These cupcakes are tangy, bitter and sweet – definitely unique! Makes 15 cupcakes.

Printable Recipe

Grapefruit Poppy Seed Cupcakes adapted from Baked: New Frontiers in Baking

7/8 c (174g) sugar
zest of 2 grapefruit
1 1/3 c + 2 Tbsp (200g) flour
1/4 c cornstarch
1 1/2 tsp baking powder
1/2 tsp baking soda
1/4 tsp salt
1 Tbsp poppy seeds
1/4 c (60g) butter
1/4 c (52g) shortening
1 egg yolk
3/4 c freshly squeezed grapefruit juice, cold
2 egg whites
1/4 tsp cream of tartar

Preheat the oven to 325F. This recipe yields 15 cupcakes, so line the appropriate amount of cupcake tins and set aside.

Place the sugar and grapefruit zest in a small bowl and rub together with your fingers until it looks like wet sand and is very fragrant. Set aside.

In another bowl, whisk together the flour, cornstarch, baking powder, baking soda, salt and poppy seeds. Set aside.

In your mixing bowl, combine the butter and shortening and cream together until well combined, about 3 minutes. Scrape down the bowl and add the sugar. Beat until light and fluffy, about 5 minutes. Scrape the bowl again and add the egg yolk and vanilla. Beat until just combined.

Alternating, add the dry ingredients and the grapefruit juice to the batter, beginning and ending with the dry ingredients. Begin with 1/3 of the dry, then add 1/2 of the wet, and repeat. Set aside.

In another bowl, beat the egg whites and cream of tartar to soft peaks. Be very careful not to over beat!

Take 1/3 of the whipped egg whites and fold it gently into the batter. Add the remaining egg whites and fold just until no streaks remain. Divide between the 15 cupcake liners and bake until the top springs back when pressed, 18-20 minutes. Cool pans on rack, de-panning the cakes after 2 minutes. Allow to cool completely.

Grapefruit Syrup

1/2 grapefruit, juiced
1 Tbsp sugar
2 Tbsp water

Combine all ingredients in a saucepan and bring to a boil, stirring occasionally. Remove from heat and strain, reserving the liquid and tossing out any solids.

Strawberry Rhubarb Jam

1 1/2 c (100g) strawberries, chopped
1 1/2 c (150g) rhubarb, chopped
1 Tbsp grapefruit juice, freshly squeezed
1/4 c (50g) sugar

Combine all ingredients in a saucepan and simmer, uncovered, over medium low heat until most of the liquid has evaporated and the jam is quite thick. Set aside to cool.

Cream Cheese Swiss Meringue Buttercream

3 (100g) egg whites
2/3 c (130g) sugar
10 Tbsp (142g) butter, cubed and at room temp
1 tsp vanilla
4 oz (113g) cream cheese, cubed and at room temp

In the base of a double boiler, bring water to a simmer. In the top bowl (or just a bowl to place over a pan of simmering water) combine the egg whites and sugar and whisk constantly until the mixture is hot to the touch (160F on a candy thermometer if you want to be completely accurate), about five minutes depending on the original temperature of the eggs. When the mixture has warmed sufficiently, pour it into the bowl of your stand mixer and whip on high speed until the bottom of the bowl is room temperature, ten to fifteen minutes. When the bowl is no longer warm, turn the mixer to medium-low and begin adding the butter piece by piece. Let each chunk incorporate completely before adding the next and don’t rush the process!

After all of the butter has been added, add the vanilla and turn the speed back to high. Whip for about 3 minutes or until the buttercream comes together. Turn the speed down to low and add the cream cheese, then mix on medium to fully incorporate.

Grapefruit Poppy Seed Cupcakes
Sharp knife
Grapefruit Syrup
Strawberry Rhubarb Jam
Cream Cheese Swiss Meringue Buttercream
Piping bag, piping tips, sprinkles and gum paste flowers to decorate, if desired

Using a sharp knife, cut a cylinder in the cupcake about 3/4s of the cupcake’s height deep. Using a spoon, core out the center in one piece. Flip over and trim off part of the bottom.

Drizzle a little grapefruit syrup into the cavity, then drop in a spoonful of Strawberry Rhubarb Jam. Top with the circle of cupcake you cut out previously. Pierce the cupcake with a skewer and drizzle with a little more grapefruit syrup.

Top the cupcake with Cream Cheese Swiss Meringue Buttercream and decorate as desired.


  1. says

    Wow, those cupcakes look amazing and so pretty! Perfect for almost spring. :) I really like your simple styling for this post. Congrats on the internship also, it all sounds wonderful – you sound like a person who's just really enjoying her life, not like a suck up at all. The thought didn't even cross my mind! Well done.

  2. says

    your creations and photographs never cease to amaze me! these sound great and I bet they taste every bit as good as they look :) Great post, Kaitlin! Congrats on the internship! Sounds great :)

  3. says

    So. Gorgeous. I bet all your friends are going to be asking you to bake their wedding cakes when they get married.<br /><br />Well done on the internship as well. :)

  4. says

    You are the buttercream queen! Your cupcakes always look so perfectly iced and I love the sharp addition of grapefruit. It feels a bit wintry in the UK for these at the moment, but can imagine one taste would transport me towards spring :-)

  5. says

    Thank you all so very much! <br /><br />Zoe, I needed to hear that! I was worried! <br /><br />Ilan, I made them myself following a tutorial online, but I can&#39;t seem to find it :( You basically make a tear drop shaped bit of gumpaste and cut five segments at the fat end. Then roll each of them out over the tip of your thumb to round and thin. Set to dry, dust with petal dust if desired, and

  6. says

    Welcome back and so glad all is going so well! These cupcakes are just perfect for this Springlike weather we are having here on the Eastern Shore of Maryland.

  7. Anonymous says

    Hello. You have inspired me to FINALLY attempt Swiss meringue frosting, now that I am the proud owner of a Kitchen Aid mixer which my hubby bought for me as a complete surprise last week! Yay! A quick question about the cupcake recipe – what difference do you find (if any) that using shortening makes in your sponge recipes?

  8. says

    Thank you!<br /><br />Anonymous, hooray! What a great gift! I prefer to use butter in baking, but I think the original recipe suggested the shortening to either help keep the cakes moist or to make them more tender. Honestly though, just use all butter if you want. I&#39;m sure it wouldn&#39;t be bad in any way!

  9. says

    Hello! I want to make these tomorrow, but just noticed that you don&#39;t have the full measurement of juice needed for the cupcakes… it says 3/4, but is that cups or Tbs?<br />Thanks!!

  10. says

    I made a batch last weekend, and they came out beautifully but there&#39;s a really strange after-taste and mouth-feel, almost a numbness of the tongue that lasts for several hours. All of my ingredients were fresh, all I can think is that it&#39;s the tartness of the grapefruit or possibly the cream of tartar (because I&#39;ve never used that in cupcakes before). It&#39;s such a shame because

    • says

      That&#39;s very unusual… The cream of tartar is just to stabilize the meringue. I can&#39;t imagine it causing numbness, especially with such a small amount, but I suppose it might be possible. <br /><br />I&#39;m thinking it must be the grapefruit you used. Perhaps it was slightly under-ripe and, therefore, extra tart? I&#39;m sorry they turned out that way :(

  11. says

    Yeah, it&#39;s really strange. I did have a glass of grapefruit juice squeezed from the same fruit, and that didn&#39;t cause any problems. I&#39;m sure it&#39;s not in the frosting either… maybe it&#39;s the rhubarb – could that be under-ripe and cause such a thing? Maybe the grapefruit zest had traces of chemicals left on the outside after I washed them? The cakes tasted great though!

  12. says

    I tried these! They were very tasty! I didn&#39;t have any problems with numbness, but I did have trouble getting the buttercream to the right consistency. My buttercream came together fine, but as soon as I added the cream cheese it became soupy. I kept trying to get it back to the right consistency for probably an hour with no luck. Anyone have advice on this? I want to try it again

    • says

      It should incorporate straight away. Using reduced fat cream cheese could make it sloppy, or if the cheese is too cold it&#39;ll have trouble incorporating – I always leave it out on the bench with the butter for a few hours before using it. Was it an unusual brand? Maybe it&#39;s just not suitable for mixing.

    • says

      I used Philadelphia regular cream cheese, which I would guess is a pretty standard brand. It may have been the temperature. I usually cube my butter and leave it out when I start the SMB, and I did the cream cheese at the same time. Next time, I&#39;ll make sure I&#39;m truly at room temp for the cream cheese. Thanks for the help!

  13. Anonymous says

    I tried this recipe and I had the same problem with it turning soupy and I make swiss meringue buttercream all the time but this was my first attempt at cream cheese swiss meringue

    • Anonymous says

      I had the same issue…perfect until I added the cream cheese. The soupy, soupy – Philadelphia Brand, Regular Fat. I ended up beating and beating and it never really got better. I&#39;m hoping some time in the fridge will make it usable…

  14. Michelle says

    Hi, I tried this recipe and it went soupy too, however, I used Philadelphia Cream Cheese too. I noticed others saying they had used this brand so perhaps this is the problem! I ended up mixing some of the curdled cream cheese meringue mix with some other meringue buttercream I had and it came out OK. Will try again but with a different cream cheese brand as it tasted great! Thank you for the

  15. Anonymous says

    For the people having trouble, I used a total of 2 sticks of butter and added about 1/2 cup of powdered suger to try to salvage the recipe and it finally came together. Hopefully this helps some people! Also, if your SMB won&#39;t come together, sometimes rubbing a cubed of ice along the bottom of the bowl while beating helps.

  16. Danielle in NH says

    I was so excited to find a recipe for Cream Cheese SMBC – I have tried a few different versions and none have even come close to matching the consistency of a straight SMBC. Unfortunately, I will add this recipe to the list as well. Although the flavor is fabulous, it is NOT a frosting that I would be able to ice a cake with – it is WAY too soft. It was delicious as a filling! I am not new to

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