Funfetti Cake with Cream Cheese Mousse and Ermine Buttercream

Steps

Funfetti Cake

1. 1

   Make the cake layers. Heat the oven to 350°F (180 °C) (175°C (350 °F)). Grease two 8-inch round cake pans, line the bottoms with parchment, and lightly flour the sides.

2. 2

   Whisk the flour, baking powder, and salt together in a medium bowl. Set the dry mixture aside.

3. 3

   Beat the softened butter and sugar in a stand mixer or with a hand mixer on medium speed until pale, light, and fluffy, about 3–4 minutes.

   Start 4-minute timer
4. 4

   Add the eggs one at a time, beating well after each addition. Mix in the vanilla. Scrape down the bowl as needed.

5. 5

   Add the dry ingredients in three additions, alternating with the milk in two additions. Mix on low speed only until the batter is nearly combined; do not overmix.

6. 6

   Fold in the rainbow sprinkles by hand, using as few strokes as possible so the colors do not bleed into the batter.

7. 7

   Divide the batter evenly between the prepared pans and smooth the tops. Bake for 28–35 minutes, until the centers spring back lightly and a toothpick inserted in the middle comes out clean or with a few moist crumbs.

   Start 35-minute timer
8. 8

   Cool the cakes in their pans for 10 minutes. Turn them out onto a rack, remove the parchment, and cool completely before filling and frosting.

   Start 10-minute timer

Cream Cheese Mousse

9. 9

   Make the cream cheese mousse. Beat the softened cream cheese, powdered sugar, and vanilla until smooth and creamy. In a separate bowl, whip the cold heavy cream to medium-stiff peaks.

10. 10

    Fold the whipped cream into the cream cheese mixture in two or three additions until smooth and airy. Refrigerate the mousse until needed.

Ermine Buttercream

11. 11

    Make the ermine buttercream base. Whisk the milk, flour, sugar, and salt together in a saucepan over medium heat. Cook, whisking constantly, until thick enough to coat the whisk, about 5–8 minutes.

    Start 8-minute timer
12. 12

    Transfer the cooked mixture to a shallow bowl. Press plastic wrap directly against the surface and cool completely to room temperature. The mixture and the butter must be at the same temperature before combining.

13. 13

    Beat the softened butter until very pale and fluffy, about 5 minutes. Add the cooled milk mixture one spoonful at a time, beating thoroughly after each addition. Beat in the vanilla and continue mixing until silky and light.

    Start 5-minute timer

Assembly

14. 14

    Assemble the cake. If necessary, level the cake layers with a serrated knife. Place one layer on a cake board or serving plate and pipe or spread a buttercream border around its edge.

15. 15

    Spread the cream cheese mousse inside the buttercream border. Place the second cake layer on top and press gently to level the cake.

16. 16

    Cover the cake with a thin crumb coat of ermine buttercream. Chill until firm, then apply the remaining buttercream and decorate with additional sprinkles if desired.

17. 17

    For make-ahead storage, chill the assembled cake until firm, wrap it well, and freeze. Thaw it in the refrigerator, then allow it to sit at room temperature until soft enough to serve.