Step 1

Preheat the oven to 350°F. Line the bottom and sides of the cake pan with parchment paper.

Step 2

Whip Eggs: In a large heat-proof bowl, add the eggs, sugar, vanilla, and salt. Place this bowl inside a larger bowl that's been filled with hot water (bain-marie). Using a hand mixer, beat the eggs on high speed until soft, fluffy, and pale yellow ribbons form, about 8 to 10 minutes. Replace the hot water halfway through as it cools down. See Note 1.

Step 3

Add Flour: Sift in the flour in three parts, gently folding after each time.

Step 4

Add Butter: To help incorporate the butter, mix 3 heaping spoonfuls of the batter into the warmed, melted butter. Next, gently fold the butter mixture into the batter. See Note 2.

Step 5

Bake: Pour the batter into your cake pan and bake at 350°F until a toothpick inserted in the center comes out clean. For one 9-inch round pan, about 25 minutes. For two 6-inch round pans, about 18 minutes.

Step 6

Cool: Remove all parchment paper and allow it to cool completely on a cooling rack.

Step 7

Using a whisk attachment, beat the mascarpone cheese and powdered sugar together until fluffy and combined. Next, add 1/3 of the heavy whipping cream and mix on low. Once combined, add the remaining heavy whipping cream and beat on high speed until light and fluffy.

Step 8

Cake syrup: Make cake syrup by dissolving the sugar in hot water. Set aside.

Step 9

Fill: Slice the cake into even layers using a leveler. Working with the bottom layer, brush on a layer of cake syrup then add a thin layer of frosting. Top with berries and apply another thin layer of frosting on top. Add the next layer of cake and repeat the previous steps for the cake syrup, frosting, and berries. Note: Aim to use up all the cake syrup as this adds moistness to the sponge layers.

Step 10

Decorate: Frost the top and sides of the cake and decorate with more berries. Serve and enjoy!