Mango Jam Filling: Dice one large mango, add to a saucepan with two passion fruit pulps and 50g sugar. Simmer until thickened, about 10 minutes.
Prepare a thin cornflour paste with 2 tsp cold water. Stir into the jam for 30 seconds to avoid lumps. Remove from heat and let it cool.
For store-bought jam, stir in cornflour mix while boiling. Adjust thickness with water. Can be prepared in advance and refrigerated.
Cake Batter: Preheat oven to 160°C / 140°C fan / 325°F / Gas 3.
Grease and line two 23cm (9inch) springform pans.
Cream butter and sugar in a large bowl until fluffy.
Add vanilla, beat in egg yolks one at a time, then mix in yogurt.
Sift flour, baking powder, salt, and baking soda into the mixture; combine well.
Whisk egg whites until soft peaks form in a separate bowl.
Blend 1/3 of egg whites into batter, then fold in the rest with 100g diced fresh mango (optional).
Baking: Divide batter between pans and bake for 30 mins until golden; toothpick should come out clean. Don't overbake.
Cool cakes for 15 mins, then release from pans and cool on a rack.
Frosting: Beat cream cheese and butter until smooth. Add half of the icing sugar, mix well. Add vanilla and salt, then remaining sugar for desired consistency.
Assembly: Place one sponge on a cake board, spread a thin layer of frosting, add cooled mango jam, and second sponge. Ice top and sides of the cake.