ready in 4 h. 50 min.
Preheat oven to 180°C | 350F | gas 4. Line a baking sheet with parchment paper.
In a medium bowl, beat the egg whites until stiff peaks form. In a separate bowl beat the egg yolks and 1/2 cup sugar until light and fluffy. Combine the flour, cornstarch and baking powder.
Fold the egg whites into the egg yolk mixture. Fold the egg mixture into the flour mixture until the batter is light and airy.
Pour the batter onto the prepared baking sheet and smooth the top with the back of a spoon. Bake for 10 to 12 minutes. Cool in the pan and cut into three equal rectangles.
Meanwhile, sprinkle half of the wine over the candied fruit. Soften the gelatin in cold water according to package instructions.
Combine 3 cups mascarpone with the remaining 1/4 cup sugar and Marsala, stirring until smooth. Pour the gelatin and vanilla sugar into a small saucepan and heat, stirring constantly until the sugar is dissolved. Stir in the remaining mascarpone, stirring to incorporate.
In a large chilled stainless steel bowl, beat the heavy cream and the vanilla sugar until stiff. Fold half of the cream into the mascarpone mixture.
Place 1 of the sponge rectangles on an elongated cake plate. Spoon 1/2 of the candied fruit over the top, followed by a thick layer of about 1/3 of the mascarpone cheese mixture. Repeat with the process to create a second layer. Top with the third rectangle of sponge cake. Fold the remaining whipped cream into the remaining marscarpone and cover the top and sides of the cake.
Chill in the refrigerator for at least four hours. Slice and serve.