Chiffon Cake:
Preheat oven to 325F (conventional) and line a 9x13" pan with parchment paper
To the egg yolks, add sugar, salt, vanilla, oil and milk and whisk until combined
Sift in the flour and cornstarch and whisk until combined
Separately, in a clean bowl and using a clean whisk, whip up the egg whites and cream of tartar until the egg whites are stiff and glossy. Do this on medium speed, and make sure the egg whites are properly whipped up to stiff peaks, otherwise the cake will be dense
Add a third of the egg whites to the remaining batter and gently fold it in. Then add the remaining egg whites and fold until combined. Be extra gentle and slow in this step - it is easy to overmix and that will cause your cake to be dense
Bake for about ~13-15 minutes until the cake is done
While the cake is still warm, dust it generously with powdered sugar and turn it over on a sheet of parchment paper. Remove the parchment paper from the bottom, and dust more powdered sugar on that side too
Carefully roll up the cake along the length (with the short side towards you), with the parchment paper in there as well. This will give your cake 'muscle memory' so it can roll up easily later. It is important to do this while the cake is still warm, and not do it too tightly as that will cause the cake to crack
Let the cake fully cool down
Mango simple syrup:
Mix the water, sugar and mango chunks in a saucepan and simmer for a few minutes until the sugar dissolves and the mango seems to be soft (no need to turn it into a thick syrup)
Strain the mango chunks out, and then let the syrup cool down
Chantilly cream:
Whip up the heavy cream with the sugar and vanilla using the balloon whisk attachment of your stand mixer until it reaches firm peaks
Assembly:
Carefully unroll the swiss roll cake
Drench it generously with the mango simple syrup, using a pastry brush. You may not use all of it
Evenly spread on a thick layer of the whipped cream. More the merrier, but not so much that you can't roll up the cake
Cover the cake with thinly sliced mango, trying to get mango everywhere
Now, carefully roll the cake up again in the same direction as before. Don't do this too tightly as that will cause the filling to get pushed out. But also not so loose that you don't get a nice swirl
Refrigerate for 30 minutes
Decoration:
Trim off the edges of the cake with a sharp serrated knife
Dust more powdered sugar on top
Pipe on the remaining whipped cream in any design you like, and decorate with finely chopped mango
Serve and enjoy!
