1 Preheat oven to 180°C | 350F | gas 4. Line a baking sheet with parchment paper.
2 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.
3 Fold the egg whites into the egg yolk mixture. Fold the egg mixture into the flour mixture until the batter is light and airy.
4 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.
5 Meanwhile, sprinkle half of the wine over the candied fruit. Soften the gelatin in cold water according to package instructions.
6 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.
7 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.
8 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.
9 Chill in the refrigerator for at least four hours. Slice and serve.