This tropical cake features the flavors of papaya, mango, and lime.
Preheat oven to 350 degrees. Coat cake pans with cooking spray; cover bottoms with parchment, and coat again. Set aside. Put egg yolks and sugar into the bowl of an electric mixer fitted with the whisk attachment; beat on low speed until pale and thick, about 15 minutes. Transfer to a bowl.
Put egg whites into the clean bowl of an electric mixer fitted with the whisk attachment; beat on medium-high until stiff peaks form. Fold into yolk mixture.
Sift together flour and baking powder; fold into egg mixture. Fold in lime zest.
Divide batter among prepared pans, filling each two-thirds full. Bake until a cake tester inserted into centers comes out clean. Transfer to wire racks; let cool in pans slightly. Invert cakes onto racks. Remove parchment; reinvert. Cakes can be wrapped in plastic and stored up to 1 day.
6-INCH: 5 cups batter, 35 minutes; 8-INCH: 8 cups batter, 45 minutes; 10-INCH: 9 cups batter, 1 hour.
Cut each cake in half horizontally. Brush each layer with syrup. Spread 1 layer with filling. Place remaining layer on top. Frost tiers with frosting.
6-INCH: 1/3 cup syrup per layer (2/3 cup total), 1 cup filling, 1 cup frosting; 8-INCH: 3/4 cup syrup per layer (1 1/2 cups total), 2 cups filling, 1 1/2 cups frosting; 10-INCH: 1 cup syrup per layer (2 cups total), 3 cups filling, 2 cups frosting.
Make this batter recipe 2 times for a 3-tiered cake to serve 70. Bake 1 cake for each tier, and cut into 2 layers.