Preheat and prep (5 minutes): Preheat oven to 350°F (175°C). Grease a 9-inch pan and line with parchment. I skipped parchment once, and the sponge stuck – don’t do it!

Make sponge cake (15 minutes): Beat eggs and sugar on high until pale and thick, about 5 minutes. Add vanilla. Sift flour, baking powder, and salt; gently fold into egg mixture. Pour into pan, smooth top, and bake 20-25 minutes until springy. Cool 5 minutes in pan, then invert onto a rack and cool completely.

Prepare custard (15 minutes): Heat milk in a saucepan until steaming. Whisk yolks, sugar, cornstarch, and salt in a bowl. Slowly pour in hot milk, whisking. Return to saucepan, cook over medium, stirring until thickened (2-3 minutes). Stir in vanilla. Cool, covered, in fridge.

Whip cream (5 minutes): Beat cold cream to stiff peaks. Fold half into cooled custard for a creamy filling; reserve half for the dome.

Assemble layers (15 minutes): Slice cooled sponge into three thin layers. Place one layer on a serving plate, spread with raspberry jam, then a layer of custard-cream mix. Add second layer, more custard-cream, and top with third layer. Shape remaining whipped cream into a dome on top, using a spatula to smooth.

Cover with marzipan (10 minutes): Roll out green-tinted marzipan to 1/8-inch thickness, large enough to cover the cake (about 16 inches wide). Drape over the dome, smooth gently, and trim excess. Shape a small piece of pink-tinted marzipan into a rose for the top.

Chill and finish (5 minutes): Chill cake for 30 minutes to set. Dust lightly with powdered sugar before serving for a royal homemade princess cake.

Serve: Slice carefully with a sharp knife for clean cuts, revealing the lush layers.