I think this is possibly the perfect confetti cake. It’s plush and springy and has a tender, but not overly fine crumb. It’s pleasingly yellow, like a boxed cake mix, and it seems to bake up just as reliably as a boxed mix. It’s absolutely choc-full of bright, cheerful sprinkles.
I first made the full size cake from the brilliant Butternut Bakery for a friend’s baby shower and I was really impressed by the results. But it was absolutely huge. I made a large, two layer 9” x 13” sheet cake and wound up with leftover batter that I turned into a half dozen cupcakes. I love this cake, but I thought a smaller version would be useful for my usual needs. I halved the recipe, resulting in a smaller, but not small cake. It’s a generous 2 layer 9” round cake that easily serves 12 slices, or up to 16 slightly smaller ones. Thanks to the original recipe having an even number of eggs, you don't have to do annoying things like trying to halve an egg. I also added a touch of almond extract, which I think adds a bit of complexity and depth of flavour, without adding a noticeable almond flavour.
When I first made this cake, I used a standard American buttercream. It’s not usually my go-to frosting, but for the confetti cake, I wanted to replicate the nostalgic flavour of a children’s birthday party. American buttercream transports you back to your 5th birthday perfectly. However, I found it quite stiff and hard to work with, so I was looking for ways to make the frosting a bit more pipable and spreadable. I found this great version of american buttercream over on sugarologie. This frosting is essentially an american buttercream with corn syrup (or golden syrup or another sugar syrup) replacing some of the icing sugar. These liquid sugars are called invert sugars, because they have a molecular structure that polarizes light in the opposite way to other sugars. Check out this great explanation video of this cool effect!
Honey is also an invert sugar; they generally are sugars that are able to remain liquid over time. Adding an invert sugar to your american frosting changes several things:
It decreases grittiness because a higher proportion of the sugar in the frosting is dissolved, resulting in a silkier texture.
It uses slightly less sugar overall, making the frosting just a tad less sweet than traditional american buttercream.
It makes the frosting a bit softer, and I find, easier to spread, pipe and work with.
This frosting is a bit less prone crusting, unlike traditional american buttercream which sets into a fairly hard crust shortly after frosting. This is helpful for doing your crumb and second coats of frosting without the frosting getting crumble.
I know lots of folks don’t love how intensely sweet american buttercream is, so making it a bit less sweet can be a plus (Normally I agree that American buttercream is a bit too sweet, butI actually think American buttercream tastes great on this cake, which is clearly supposed to taste like childhood!). This modified American buttercream is still plenty sweet for any child or adult! For the invert sugar, I used half light corn syrup and half golden syrup, partly because I thought it would taste great, and partly because I only had a bit of each left in the cupboard and I didn’t want to go to the store.The combination works really well: the corn syrup has quite a neutral flavour, and is slightly less sweet, while the golden syrup is a little bit toasty-caramelly and a bit sweeter. The combination is great, but either syrup on its own would also work well. I think the sweetness of this buttercream, or traditional American buttercream, calls for a generous amount of salt for balance. I use both salted butter and a little bit of added salt in the frosting, unsalted butter is fine too. Just salt to taste either way.
confetti cake
Adapted from Butternut Bakery
½ cup butter at room temperature
1 cup granulated sugar
¼ cup vegetable oil
2 large eggs, room temp
1 tbsp vanilla extract
½ tsp almond extract
1 ½ cups + 2 tbsp all purpose flour
1 1/4 tsp baking powder
1/4 tsp baking soda
1/2 tsp salt
1/4 cup full-fat sour cream or full-fat plain yogurt, at room temperature
½ cup buttermilk, room temp (or whole milk soured with 2 tbsp of lemon juice)
⅓ cup rainbow jimmies sprinkles
Heat the oven to 350° F. Line the bottom of two 9” pans with parchment.
Combine flour, baking powder, baking soda and salt in a large bowl. Whisk thoroughly and set aside.
In the bowl of a stand mixer, beat butter and sugar on medium-high speed for about 3 minutes, or until very fluffy and pale in colour. Reduce speed to low and stream in oil slowly. Add eggs one at a time, scraping the bowl after each egg. Mix in the yogurt or sour cream and vanilla and almond extracts on low speed.
Alternating, add the milk and the dry ingredients in two additions each, dry, wet, dry, wet, mixing on the lowest speed. Scrape the bowl really well to make sure there are no streaks of any ingredients unincorporated.
Tip: Drape a very large tea towel over the top of your mixer when first mixing flour, to avoid a big flour cloud.
Take the bowl off the mixer and gently fold in the sprinkles. Avoid stirring too much or the colours will run and make the cake look muddy.
Divide the batter between your prepared pans (you can weigh the pans with the batter if you want to make them super even). Bake for about 30-35 minutes. They are ready when the top of the cake is golden brown and springy when gently pressed, and a toothpick inserted in the centre comes out clean, without any wet batter.
Let the cakes cool in the pans for about 15 minutes, then run a paring knife along the edge to release the sides. Turn cakes out onto a wire rack until fully cooled.
Wrap cake in cling wrap and chill in the fridge for several hours or overnight (or freeze for about 30 mins). A chilled or semi-frozen cake will be easier to frost. A room temperature the cake will be softer and pull crumbs into the frosting.
updated american-ish buttercream
Adapted from Sugarologie
1 1/2 cups butter, room temperature
2/3 cups light corn syrup or golden syrup (I used 1/3 cup of each)
1 1/4 cups powdered sugar
1/8 teaspoon fine salt or to taste
1 teaspoon vanilla extract
⅛ tsp almond extract
3-6 tablespoons of heavy cream, room temperature
In the bowl of a stand mixer, add butter, ¾ cup powdered sugar, mix on medium high for 2 minutes with the whisk attachment, or until well combined and very fluffy.
Add syrup in several additions, mixing thoroughly between each addition and scraping down the bowl well. When all syrup is in, mix for another minute on medium high, to ensure that the syrup is entirely emulsified in the frosting.
Add the remaining sugar a little at a time, tasting to see when the sweetness is at your desired level. You don’t need to add all the sugar, just dial it in to the taste and texture you prefer. Add in vanilla and almond extract and salt and beat with the paddle attachment until fully incorporated, making sure to scrape the sides of the bowl well.
If you want to make the frosting in advance, press cling wrap directly onto the surface of frosting and store in the fridge. Bring back up to room temperature and re-whip with the paddle attachment before using.
assembly
cake layers, chilled
frosting, room temperature
lots of sprinkles
Place one cake layer on a cake turntable, if you have one, or on a sturdy, flat plate, cake stand or board (whatever you would like to serve the cake on).
Using an offset spatula, cover the entire cake with a thin layer of frosting. This doesn’t need to be even or tidy, just make sure the whole cake is covered so no cake shows through. This crumb coat will seal all the cake crumbs inside the frosting so none come out and mess up your finished frosting. Chill the cake in the fridge for 20-30 minutes to set the crumb coat.
Taking more time and care, frost the whole cake all over again with a second thin layer of frosting. Use the offset spatula to apply the frosting and give it an initial smoothing. Then use a bench scraper to make the sides straight. Hold the bench scraper straight up against the side of the cake and turn the cake so the bench scraper pulls off any excess frosting to make the sides straight and smooth. I made a little swirl on the top of the cake, you could pipe rosettes or a border, or leave it smooth. Add sprinkles generously, in a design that appeals to you: evenly all over, or just in a border along the edge, or in little clumps and bunches all over. Serve to children and childish adults to the delight of all.
