Preheat the oven to 180 degrees. Rectangular cake pan to grease and flour them.
Beat egg whites with 2 tablespoons sugar in a lush lather.
In a separate bowl, mix remaining sugar with flour, baking powder and starch. Sift in the whites and mix gently from the bottom up. In the end, add the oil, mix well.
Put the dough in a prepared form. Bake for 40-50 minutes, until a toothpick will not come out of the cupcake dry.
Ready cake cool slightly and remove from the mold.
Melt chopped chocolate and butter in a water bath, stir. Cover cooled cake with glaze.