Beat eggs with a pinch of salt until foamy. Start adding sugar a few tablespoons at a time. Add next portion once previous sugar has been dissolved.
Continue beating egg and sugar mix for 10 more minutes (should take around 15 minutes total). Stand mixer will be handy.
Mix corn starch with flour.Sift in corn starch and flour mix into the beaten eggs. Fold it gently moving your spatula from the bottom to the top. Once first portion of flour mix is incorporated, add in another portion. Continue until you have used all the mix.As a result you should get very light and airy batter.
Grease and flour the baking pan, remove access flour.Pour in the sponge cake batter into a baking pan. Level with a spatula if needed.
Bake in a preheated to 320F oven for 40-50 minutes.
Do a toothpick test at 40 minute mark. If toothpick come out dry (not sticky and without any crumbs on it) sponge cake is ready. Otherwise leave for another 5-10 minutes.
Let the cake cool in the pan. Remove from the pan. Using a cotton thread or a big bread knife cut the cut horizontally in half.
Squeeze juice from 3 oranges and 1 lemon. Add a bit of water if needed to make it to 1½ cup.
Mix together granulated sugar and corn starch. In a small stove-top pot add juice, corn starch and sugar mix. Whisk well until smooth and lumps free mix. Heat on a stove-top whisking continuously until the mixture thickens.
Let the curd cool. Add in 2-3 tablespoons on whipping cream until medium thick consistency. Whisk well.
Beat Mascarpone cheese. In a separate bowl beat whipping cream with confectioners sugar.
Mix whipped cream with Mascarpone cheese, adding a few tablespoons at a time.
Assemble the cake:
Add a spoon of Mascarpone cream in the center of a serving plate if you want to prevent the cake from moving.
Set first layer of sponge biscuit. Add half of Mascarpone cream, top with half lemon curd.
Cover with the second sponge cake layer and repeat the process.
I like to grate some lemon zest on top of the cake. It’s simple and nice decoration and adds another lemony note.
Layer Cake with Mascarpone and Lemon Curd https://www.italianrecipebook.com/lemon-layer-cake-with-mascarpone-and-lemon-curd/