South Tyrolean Buckwheat cake

250g butter

250g sugar

250g buckwheat flour

250g grated almonds

6 eggs

optional baking powder

Mix softened butter, 150g of the sugar and egg yolk until foamy. Mix in buckwheat flour and almonds. Whip egg whites but keep it on the softer side. Add the rest of the sugar to the egg whites.  Mix egg whites with the dough. Bake  at 355 degree for 1h and turn off heat.  When cold cut in half and fill with Lingonberry jam and dust with sugar for decoration.