Whip 100 g butter, sugar, brown sugar, vanilla extract and beet syrup until creamy with the whisk of the hand mixer. Stir in the egg. Mix baking powder, spices and flour. Stir the flour mixture into the butter mixture.
Place a cake frame (20 x 30 cm) on a baking tray covered with baking paper, add the dough and smooth it down. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: see manufacturer) for approx. 15 minutes.
Remove and let it cool down.
Whip 50 g butter, icing sugar and cream cheese with the whisk of the hand mixer until creamy, spread loosely on the cake base and chill for approx. 4 hours. Remove the cake frame and sprinkle with a little nutmeg.
Cut the cake into small pieces.