To start prepare the stuffing: take a medium Apple, preferably sour, cored and cut in cubes. Then season with lime juice (to taste, or the eye))) and mix well and set aside aside.

Turn on the oven to heat up to 180 degrees, get the eggs, separate into whites and yolks. In proteins add a pinch of salt and whisk until a thick foam.

Take sugar - I used sugar of Demerara TM Mistral, its taste can be very useful here! Yes, the cake turns out very sweet, so if you want you can slightly reduce the amount of sugar, for example, grams to 50.

RUB the yolks with sugar, add the mascarpone, stir again. Then add flour, sifted with baking powder, stir until smooth and gently, with a spatula, beat in the whipped whites, the main thing - time to stop!)

Now we give the cake to stand for 10 minutes, meanwhile prepare the form - I had ceramic and I have it lined with baking paper. Then mix the dough with chopped apples and spread in the form, knock a bit of form with the dough and into the oven! Bake a cake, you should first at 180 degrees for 20 minutes - then check and if the cake started to brown, reduce the temperature to 160 degrees and bake for another 20-30 minutes. Check for readiness with a toothpick.

The finished cake to cool in the form for 10-15 minutes, then remove and allow to cool completely, then slice, sprinkle with powdered sugar and a little zest from the lime and served with a Cup of hot coffee or tea.