Beat softened butter with sugar until foamy, add eggs one by one, then sour cream, honey, a portion of zest, baking powder. Mix well. Add sifted flour and knead pastry.
Put the pastry on a covered with wax paper and greased baking tray and bake in preheated to 360oF (180oC) oven for 30-35 minutes. Cool the ready sponge cake and slice into halves diagonally.
To make filling, whip cream with sugar powder and vanilla sugar. Reserve ¼ of the cream for topping, mix the rest with the main part of fried nuts.
Spread the bottom cake with the cream-nut mass, cover with the second cake and press slightly. Top with the rest of the cream using piping tube, sprinkle with zest and the rest nuts.
Refrigerate the cake for 5-6 hours before serving.
