All Hail the Milk Bar Birthday Cake!!!! This cake is probably one of the most famous things in foodie pop culture, and for good reason. It’s not just delicious but it’s well thought out. Christina Tosi (a.k.a. dessert legend/dessert genius/my culinary spirit animal) created this beautiful thing with so much intention. This is not just a typical cake. There’s layers, and frosting, cake crumbs, sprinkles, and even a vanilla flavored cake soak. This my friends, is a masterpiece.
If you couldn’t tell already, I’m a HUGE fan of Christina Tosi. I’ve probably watched her Netflix Chef’s Table: Pastry episode a hundred times. I have the Milk Bar cookbook. Visiting one of her Milk Bar bakeries has been on my foodie bucket list for quite sometime. Last year (fall 2018) my husband and I took what we like to call “a road trip of a lifetime” and visited some amazing places throughout the east coast with a last destination being Washington D.C. While in D.C. you know I had to stop at Milk Bar to not only breath in the place but to get some of the goods. Well let me tell you, this place lives up to the hype. I’m not ashamed to say we tried the cereal milk soft serve. a piece of crack pie, a slice of birthday cake and one of every cookie on the menu! All of them super tasty and creative.
Constructing a Milk Bar Birthday Cake yourself
Like I mentioned above, there’s a lot to this cake. This is not your bake-a-cake-and-frost-it type of cake. It’s so much more. It may seem like a lot but it’s not. It’s all about the details of flavor and texture.
Cake Layers: the cake recipe itself is baked in a quarter sheet pan ( 9x13inch ) and then the layers are cut out using a pastry ring.
Frosting: I love this frosting because it’s not overly sweet like a lot of cake frostings. Butter, a little bit of cream cheese, and few extra ingredients whip up into a creamy, delicious frosting. The recipe doesn’t make a ton of frosting. Christina doesn’t frost the sides of her cakes, so you just need enough for the tops of each layer. The cake itself is so good you don’t need a ton of frosting.
Birthday Cake Crumb: a delicious detail to adorn any birthday cake with. You make the cake crumb separately and use it as a garnish to build the cake. Use it between each layer of cake, pile it on thick on the crown of the cake, or maybe just sprinkle it, it’s up to you – but this cake wouldn’t be complete without it.
Cake Soak: Her cake soak is so simple but so necessary. Milk plus clear vanilla extract. That’s it. Spoon it over each layer before you frosting it and watch it the cake just drink it up, it literally disappears before your eyes. Don’t drench each layer in it, just 2 or 3 spoonfuls is enough. It’s something so simple but so magical. You may never make another cake without it!

Ingredients
For the Cake:
- 4 tablespoons unsalted butter room temperature
- 1/3 cup vegetable shortening
- 1 and 1/4 cup granulated sugar
- 3 tablespoons light brown sugar tightly packed
- 3 large eggs
- 1/2 cup buttermilk
- 1/3 cup grapeseed oil
- 2 teaspoons clear vanilla extract
- 2 cups cake flour
- 1 and 1/2 teaspoons baking powder
- 3/4 teaspoon salt
- 1/4 cup + 2 tablespoons rainbow sprinkles divided
For the Birthday Cake Crumb:
- 1/2 cup granulated sugar
- 1 and 1/2 tablespoons light brown sugar tightly packed
- 3/4 cup cake flour
- 1/2 teaspoon baking powder
- 1/2 teaspoon salt
- 2 tablespoons rainbow sprinkles
- 1/4 cup grapeseed oil
- 1 tablespoon clear vanilla extract
For the Frosting:
- 8 tablespoons 1 stick unsalted butter (room temperature)
- 1/4 cup vegetable shortening
- 2 ounces cream cheese
- 1 tablespoon glucose*
- 1 tablespoon corn syrup
- 1 tablespoon clear vanilla extract
- 1 and 1/4 cups powdered sugar
- 1/2 teaspoon salt
- a pinch of baking power
- a pinch of citric acid*
For the Cake Soak:
- 1/4 cup milk
- 1 teaspoon clear vanilla extract
Instructions
Start by making the cake:
- Preheat oven to 350 degrees and line a 9x13 inch baking sheet pan with parchment paper and lightly spray with non stick baking spray. Set aside.
- Combine the butter, shortening, sugar and brown sugar in the bowl of a stand mixer with a paddle attachment. You can also use a large mixing bowl and a handheld mixer if you don't have a stand mixer. Cream the ingredients together on medium speed for 2 to 3 minutes. Scrape down the sides of the bowl and add in the eggs and beat on medium speed for another 2 to 3 minutes. Reduce the mixing speed to low and slowly pour on the buttermilk, oil and vanilla extract. Increase the speed to medium high and let everything mix together for 4 to 6 minutes. Do not skip on time. When down there should be no streaks of liquid or fat in the batter. Scrape down the sides of the bowl. On very low speed, add the flour, baking powder, salt and the 1/4 cup of rainbow sprinkles to the mixture and mix to combine, for about 45 to 60 seconds. Do not over mix the batter.
- Pour the batter onto the baking sheet and smooth it out with a spatula. Sprinkle the remaining 2 tablespoons of rainbow sprinkles over the top of the batter. Bake cake for 30 to 35 minutes. Insert a toothpick in the center to test for doneness. Once done baking, remove the cake from the oven and allow to cool completely before frosting.
Make the birthday cake crumb:
- Preheat the oven to 300 degrees. Lightly spray a baking sheet with non stick baking spray and set aside.
- In a mixing bowl, combine both sugars, flour, baking powders, salt and sprinkles. Mix the ingredients together just to combine them. Add in the oil and vanilla and mix together to combine with the dry ingredients. Mix until you get clumps of "cake crumb". Some pieces will be small, some will be bigger. Pour the cake crumbs onto the baking sheet and bake for 20 minutes. About halfway through baking, take a spatula and lightly toss them around so they evenly bake. Once finished baking remove from the oven and allow to cool completely. If you make the crumbs ahead of time you can store them in an airtight container to maintain freshness.
Make the frosting:
- Combine the butter, shortening and cream cheese in a mixing bowl and mix together on medium speed using a hand held mixer or a stand mixer with a paddle attachment, for about 2 minutes. Scrape down the sides of the bowl and add in the glucose*, corn syrup, and vanilla extract. Continue mixing for another 2 to 3 minutes to combine. Scrape down the sides of the bowl once more and add in the powdered sugar, salt, baking powder and citric acid. Mix the ingredients on low speed for about 1 minute (so the sugar doesn't fly everywhere) and then go back up to medium speed mixing for 2 to 3 minutes, until everything is thoroughly combined and fluffy.
Make the Cake Soak:
- In a small bowl combine milk and vanilla extract and give it a quick stir.
Assembling the Cake:
- Use a pastry ring to cut out 2 cake rounds to make your top and middle layer of the cake. Use the remaining cake scraps to make the bottom layer of the cake. For this, I punched out 2 half circles of cake scraps and just fitted them together to make the bottom layer. Place the first layer (bottom layer) of cake on a plate. Use a few spoonfuls of cake soak over the top of the cake layer, it'll absorb directly into the cake. Then frost a small amount of frosting over the top over the layer, covering the top of the layer. Sprinkle a third of the birthday cake crumb over the frosting. Add the second layer of birthday cake over the cake crumbs. Repeat with the cake soak, frosting and cake crumbs. Add the third (top) layer of cake and repeat the process once more; cake soak, frosting, and cake crumbs.
- Cake can be served immediately or stored in the refrigerator (preferably in an airtight container or box so it doens't dry out).