This showstopping cake could not be easier! Brownie layers perfectly compliment white cake and then are topped with a beautiful buttercream rosette. Cake perfection! Don’t miss my classic American Buttercream Frosting!
Before you go any further I want you to know two things:
- I am sharing the semi-homemade version of the recipe here. That is one box of white cake and one box of brownie mix.
- You can most definitely make this from scratch! You can use my White Cake Recipe and my favorite From-Scratch Brownie Recipe.
- 1 cup (2 sticks or 227g) unsalted butter, room temperature
- 1/2 cup (115g) shortening
- 2 teaspoons fresh lemon juice or 1 tsp lemon extract, pure vanilla extract, or almond extract
- 6 cups (just over a pound) confectioners' sugar
- 1/4 cup (60g) whole milk*
- 2 teaspoons meringue powder**
- 1/2 teaspoon table salt
- In a stand mixer with the paddle attachment, cream shortening and butter on medium-high until fully combined and fluffy, about 3 minutes.
- With mixer on low speed, add lemon juice (or extracts) and salt.
- Slowly add sugar, one cup at a time. Add meringue powder. (The mixture will appear dry.)
- Add in milk. Turn the mixer up to medium-high (or high) and beat until light and fluffy (approximately 5 to 8 minutes).
- *You may need to add more milk to reach your desired consistency. Start with the 1/4 cup and if the buttercream is still too dry, add in more milk 1 tablespoon at a time until you reach the desired consistency. Make sure the mixer is on low speed when adding in milk and give it at least 30 seconds between each addition.
- **You can omit meringue power if you prefer. To achieve the perfect piping consistency, you may need to add more confectioner's sugar.
- For extra smooth frosting with less air pockets, add buttercream to a food processor 1/2 batch at a time. Process for 3-5 minutes on high, or until frosting appears smooth and creamy like ice cream.
- Place directly into piping bags and seal with a rubber band. Can be stored in piping bag until ready to use, up to 3 months.
White Cake with Brownie and Decorator’s Buttercream
Supplies Needed to Make This Cake:
1 box of White Cake
1 box of Brownie Mix
1 Decorator’s Buttercream recipe (below)
8-inch round cake pans
Piping bag with a large star tip (like a 1M or 2D tip)
To Make this Cake:
Prepare brownie batter. Divide batter between two prepared (the right way!) 8-inch round cake pans. Bake at 350 degrees for 10 minutes, or until the brownie batter is set and starting to crust slightly.
While brownie is baking, prepare white cake according to box or recipe directions.
After 10 minutes in the oven, carefully remove brownies. Equally divide the white cake batter between the two brownie pans and return to the oven to bake for 16-22 minutes. When cake is done it will dome in the center slightly, will have pulled away from the edges of the pan, and will have nicely browned on the sides and top.
Cool completely. (To make frosting the cake easier, place in refrigerator until ready to assemble.)
How to Frost with Decorator’s Buttercream
In the Decorator’s Buttercream recipe, there is fresh lemon juice. In my opinion, this does NOT give the buttercream a “lemony” flavor, but simply helps to enhance the sweetness. You are welcome to simply use vanilla extract but try it with the fresh lemon at least once.
Try frosting your cake chilled. This rose cake design works best with a crumb coat underneath, but because it has SO MUCH FROSTING, doing a thin crumb coat is best. When you apply the crumb coat to a chilled cake, the crumbs tend to behave a little better. 🙂
The juxtaposition of a light white cake with a thick, dense fudgy brownie layer is not new! I have this cake in my book Surprise-Inside Cakes, and called the Vintage Cake. The recipe was handed down from my grandma and a family favorite!