Ingredients:

  • 3 ¾ cups All-purpose flour (sifted)
  • 2 ½ cups Granulated sugar
  • 1 ½ tbsp Baking powder
  • 1 tsp Salt
  • 1 cup Unsalted butter (softened, 226g)
  • 1 ½ cups Whole milk (room temperature)
  • 1 tbsp Vanilla bean paste or extract
  • 2 Whole large eggs
  • 6 Large egg whites
  • 8 oz Cream cheese (full fat, softened)
  • 1 cup Powdered sugar
  • 2 cups Heavy whipping cream (cold)
  • 1 tsp Unflavored gelatin
  • 1 tbsp Cold water (for blooming)
  • 1 tsp Vanilla extract
  • 1 ½ cups Unsalted butter (softened, for frosting)
  • 6 cups Powdered sugar (sifted, for frosting)
  • ¼ cup Heavy cream (for frosting)
  • 1 tbsp Clear vanilla extract
  • ½ tsp Salt (for frosting)

Instructions:

  1. Preheat your oven to 350°F (180°C) and line a 12x18-inch sheet pan with parchment paper, ensuring the paper hangs over the edges.
  2. Sift 3 ¾ cups all purpose flour, 2 ½ cups sugar, baking powder, and salt into a large bowl.
  3. Beat 1 cup softened butter into the dry ingredients using a paddle attachment until the mixture looks like coarse sand.
  4. Whisk 1 ½ cups milk, vanilla bean paste, 2 whole eggs, and 6 egg whites together, then slowly stream into the flour mixture.
  5. Pour batter into the prepared pan and bake for 30 minutes until a toothpick comes out clean and the edges pull away.
  6. Sprinkle 1 tsp gelatin over 1 tbsp cold water and let sit for 5 minutes until it forms a thick, translucent gel.
  7. Beat 8 oz cream cheese and 1 cup powdered sugar until smooth, then slowly fold in 2 cups whipped heavy cream and the melted gelatin until soft, stable peaks form.
  8. Slice the cooled cake in half vertically, spread the mousse over one side, and flip the other half on top until the filling is evenly distributed.
  9. Beat 1 ½ cups butter with 6 cups powdered sugar, cream, and clear vanilla until it reaches a spreadable, cloud like consistency.
  10. Apply a thin crumb coat, chill for 20 minutes, then finish with a thick layer of buttercream until the surface is perfectly flat and opaque.