For the dough, whisk the butter with the sugar and vanilla sugar. Then add the lemon flavor and eggs and finally stir in the flour mixed with the baking powder. Pour the batter into 12 muffin tins. Spread the blackberries on top as desired.
For the crumble, knead the softened butter with flour, sugar, cinnamon and nuts with your hands and sprinkle over the blackberries.
Bake in a preheated oven at 180 ° C for approx. 20 minutes.
Tip:
For a 28 springform pan I use twice the amount of ingredients.