Prepare pans by lining bottom with parchment paper. Do not grease.
Combine and sift four, 1/3 cup sugar, baking powder and salt. Set aside.
In another bowl, combine wet ingredients - eggyolks, oil, water. Mix until combined.
Add dry to wet ingredients.
In another clean bowl, make meringue by beating cream of tartar and egg whites. Once foam starts to form, add the sremaining 1/3 cup sugar a tablespoon at a time. Beat until stiff and glossy but not dry.
Fold the meringue in the batter mixture.
Pour in prepared pans.
Bake for 23-25 minutes for 8" pan (makes 3 pans)
Bake for 32-35 for 9"x 13" pan.
Put everything in a blender and puree. You could strain or use a sieve to remove pulps if there are any.
Whipped Cream Frosting
Put whipping cream in a bowl.
Add the vanilla and cream stabilizer and whip until double in volume.
Divide the whipped cream into two.
For half of the cream, fold in 3 tablespoons mango puree.
After the cake has thoroughly cooled. Start assembling.
Put one cake at the bottom, add mango cream and diced mango.
Add the next cake layer and top with the plain whipped cream then top with diced mangoes again.
Add the 3rd layer of cake and finsih with the remaining whipped cream coaing the cake all around. Refrigerate for at least 30 minutes to set.
Take out cake from the fridge. Spoon the mango puree gently on top of the cake. Then top with the diced mangoes.
If you can't find a ready whipped cream stabilizer, you could use gelatine to stabilize your whipped cream.
To stabilize Whipped Cream:
Use 1 tsp gelatine powder (Knoxx) for every cup of heavy cream you'll use.
Let the gelatine bloom in 2 tbsps cold water for a few seconds, then mix in 2 tbsps boiling water to dissolve completely.
Let cool a little before folding into your whipped cream.