Mix the ground hazelnuts with the flour, baking powder and cinnamon, and fold in.
Line a baking tray (approx. 30 x 40 cm) with baking paper. Place half of the dough onto the baking tray and bake at 180 °C for approximately 12 to 15 minutes .
After baking, let the base cool and carefully remove it from the baking sheet. Now bake the second half of the dough.
Meanwhile, whip 1.5 liters of cream with the cream stabilizer until stiff and carefully fold in the chocolate sprinkles.
Place the first cake layer on a cake plate and enclose it with a square cake ring. Then spread half of the cream-chocolate mixture over the layer. Carefully place the second layer on top and press down lightly. Spread the remaining cream mixture over the second layer and then chill the cake for about 2 hours.
Carefully loosen the cake frame with a knife and lift it off. Whip 200 ml of cream until stiff and decorate as desired using a piping bag. Sprinkle hazelnuts on top.
