My oldest son has a super special birthdate. He was born on Leap day and is therefore a leapling! Since his actual birthday only rolls around once every 4 years, we kind of get to pick and choose the day that works best to celebrate his birthday each year. This year we celebrated last weekend (technically it was his second birthday party…but what fun is it to just have one party?) He has been obsessed with sprinkles for a little while so I decided that a funfetti cake recipe was in order for helping him celebrate.
I searched for a while to find a recipe that I wanted to try for this cake. The one I found said that it made 3 9-inch-rounds. Since I only have 2 9-inch-round cake pans, I decided to bake it as a sheet cake and decide what to do with it after it cooled. And to be completely honest… and if you follow along on Instagram you probably already know….I made this cake twice. The first one looked beautiful but had “the texture of cornbread” as Emily described it. So I went back to the drawing board and landed on the basic yellow cake recipe from Rose Levy Beranbaum and added sprinkles at the end. The technique was quite unique but produced the tastiest, fluffiest, most flavorful cake I have ever made! I can’t wait make more of her recipes.
The ingredients for this cake recipe were – 2 sticks or 16 tablespoons of unsalted butter at room temperature, 4 eggs at room temperature, 1 1/3 cups of buttermilk at room temperature divided into 1/3 of a cup and 1 cup, 1 tablespoon vanilla, 4 cups of cake flour sifted into the cup and leveled off, 2 cups of granulated sugar, 2 tablespoons plus 2 teaspoons baking powder, and 1 teaspoon fine sea salt. I added 1/2 cup of rainbow jimmies or sprinkles.
Before doing anything else, I preheated my oven to 350 F degrees. Then the recipe called for mixing together 1/3 of a cup of buttermilk, 4 eggs and 1 tablespoon of vanilla. It was whisked together and left to the side.
The next step is already backwards to so many cake recipes I have ever read or used before. It called for placing all of the dry ingredients into the bowl of the mixmaster fitted with the paddle attachment. This was the 4 cups of sifted and leveled off cake flour, the 2 cups of sugar, the teaspoon of salt and the 2 tablespoons and 2 teaspoons of baking powder. I mixed these all together for 30 seconds and then pulled the bowl and the paddle off of the mixmaster. I thought it was so crazy to begin with the dry ingredients, but it works!
The next step was to pour the 1 cup of buttermilk and the two sticks of butter into the dry ingredients and use the paddle with my hand to slightly mix the buttermilk and butter into the dry ingredients. Then I reattached the paddle and bowl to the mixmaster and turned it on low so that the dry ingredients were all moist. I switched the mixmaster to medium and let it run for 90 seconds. Afterwards I made sure to scrape down the sides of the bowl and the bottom of the bowl to make sure all the ingredients are incorporated.
Then, with the mixmaster on speed medium, I added the egg, milk, and vanilla mixture into the batter a third at a time. I made sure the mixer ran for 20 seconds after each addition, before adding the next third. When it was all added in, I scraped down the sides of the bowl and the bottom of the bowl and then folded in a 1/2 cup of rainbow jimmies.
I prepared my baking sheet pan before I poured the cake batter into it. I brushed it with butter and placed a sheet of parchment paper onto of the butter. Then I poured the cake batter on top of the parchment paper and used an offset spatula to smooth out the top. I also tried to make sure that all of the batter was level in the pan so that it would bake evenly. This cake rose beautifully in the pan while it was baking and bubbled up in an exciting way that was fun to watch in the oven. It made it extremely easy to know when the cake was finished baking, because as soon as the bubbles stopped rising, I knew that the inside of the cake was solid and ready to be pulled from the oven. This took about 33 minutes to bake. I let it cool for 10 minutes in the pan before flipping it onto the cooling rack, removing the parchment paper, and then flipping it again onto another cooling rack. It took about 45 minutes to fully cool.
While the cake cooled, I warmed up the icing that I made the day before for the first batch of cake. (Thankfully I saved it!) I let it warm on the counter while I baked and whipped it in the mixmaster on high. I realized that it wasn’t coming together as I wanted it to. The icing was still really buttery and not light and fluffy. So I asked my flame loving husband to pull out his favorite blow torch and help me warm the buttercream. After about 10 seconds of this technique, my icing was fluffy, smooth and ready to be used. Below, I’ll show you how I made the icing.
This buttercream was a pretty standard American style buttercream. It started with two sticks of room temperature salted butter that I whipped until it was smooth. Then I added 2 teaspoons of vanilla, 5+ cups of powdered sugar and 2 tablespoons of heavy cream. I say 5+ cups because I added 5 cups and then realized that it still tasted pretty buttery and not very sweet, so I continued to add spoonfuls of powdered sugar until the flavor and texture felt correct and tasted delicious. Then I let the mixer run on high for 3 – 4 minutes to whip the icing into a smooth and fluffy state. Finally, I added a 1/2 cup of rainbow jimmies to the icing.
After the cake was fully cooled, I needed to decide what I wanted to do with the beautiful sheet pan of cake. I thought about how my husband eats cupcakes. He always tears the bottom off and puts it on top of the icing and eats his cupcake like a sandwich. This always makes me think it is an inside out cupcake and gave me the inspiration for this recipe. So I used a cupcake sized cookie cutter to cut out rounds of cake. Then I sliced them in half with a serrated knife. I stacked the open faces of the cake on top of each other and piped the whipped icing onto the sliced cake rounds. Then I topped each icing piece with a bottom slice of cake to make a cake & icing sandwich or an inside out cupcake!
- This is the only way I want to make cake in the future because it turned out so amazingly fluffy, tender, and flavorful.
- Unfortunately though, because it was so tender, it created a great deal of crumbs when cut and sliced. I think it would have benefited from being chilled before I started cutting and slicing it.
- One of my favorite things about the inside out cupcake is that it is super easy to transport and eat because the icing is on the inside.
- I heard great reviews of these cupcakes, but served them after donuts at the birthday party so we ended up with way too many leftovers at our house! Send people to come eat them!
Recipe: Inside Out Funfetti Cupcakes
- 2 sticks or 16 tablespoons of unsalted butter at room temperature
- 4 eggs at room temperature
- 1 1/3 cups of buttermilk at room temperature divided into 1/3 of a cup and 1 cup
- 1 tablespoon vanilla
- 4 cups of cake flour sifted into the cup and leveled off
- 2 cups of granulated sugar
- 2 tablespoons plus 2 teaspoons baking powder
- 1 teaspoon fine sea salt
- 1/2 cup of rainbow jimmies (Non pareil sprinkles are not recommended because their color bleeds into the batter)
- Icing – (This recipe is easily divided in half if you don’t want leftovers)
- 2 sticks or 16 tablespoons of salted butter (if you want to use unsalted butter that is fine, just add a pinch of salt or to your taste)
- 5+ cups of powdered sugar (add sugar until it reaches your desired texture and flavor)
- 2 tablespoons heavy cream
- 2 teaspoons of vanilla
- 1/2 cup rainbow jimmies
- Preheat oven to 350 F degrees. Prepare sheet pan by brushing it with melted butter and lining it with parchment paper.
- In a small bowl whisk together 1/3 cup buttermilk, 4 eggs, and 1 tablespoon vanilla and set it aside.
- In the bowl of the mixmaster add the flour, baking powder, salt, and sugar. Mix it on low for 30 seconds. Then take the bowl and paddle off the mixmaster.
- Add the 2 sticks of butter and 1 cup of buttermilk to the dry ingredients and use the paddle with your hand to mash the dry ingredients into the butter and buttermilk so that it begins to incorporate. Add the paddle and the bowl back to the mixmaster and mix on low until the flour is moist then turn the speed up to medium and mix for 90 seconds. Scrape down the sides and bottom of the bowl.
- With the mixer on medium add the egg, vanilla, and buttermilk mixture to the batter in thirds. Allow the mixer to run for 20 seconds after each third of the egg mixture is added to the batter. Scrape down the sides and bottom of the bowl with a spatula after the final 20 seconds of mixing.
- Fold the 1/2 cup of rainbow jimmies into cake batter.
- Pour the batter into the prepared pan and spread it out with an offset spatula until the batter is even and smooth in the pan.
- Bake for 30-35 minutes or until the cake stops bubbling and a toothpick inserted into the middle of the pan comes out clean.
- Allow the cake to cool for 10 minutes in the pan. Then run a knife around the edge of the pan and invert onto a cooling rack. Remove the parchment paper and then invert onto a second cooling rack to finish cooling.
- While the cake cools, make the icing by beating the butter until smooth. Then add powdered sugar, heavy cream and vanilla (also salt if using). Mix until all the ingredients are incorporated and the flavor is to your liking. It may need more sugar or heavy cream at this point.
- Whip the icing on high for 3-4 minutes until the icing is light and fluffy. (The icing can be stored in the fridge for several days. Just bring it back to room temperature and rewhip it before using)
- To make the inside out cupcakes, use a round cookie cutter to cut small circles of cake out of the sheet of cake. Slice each of the rounds in half and pipe icing onto the cut side of the cake and top with the other cut side of the cake to create an inside out cupcake.
- If not eating right away, the cupcakes can be stored in an airtight container in the refrigerator for several days. Pull them out ahead of serving them and allow them to come to room temperature.
- Enjoy these delicious inside out cupcakes!
Recipe adapted from Rose Levy Beranbaum