Blueberry buttermilk cake with crumb topping

Ingredients for 1 servings:

• 175 g butter
• 150 g sugar
• 3 eggs
• some vanilla flavor or tonka bean zest
• 275 g flour
• 1 tsp baking powder
• 1 tsp baking soda
• 100 ml buttermilk
• 400 g blueberries, fresh or frozen
• 200 g flour
• 125 g butter
• 80 g sugar
• 1 packet of vanilla sugar
• powdered sugar

Instructions

Working time approx. 30 minutes; Cooking/baking time approx. 1 hour; Total time approx. 1 hour 30 minutes

For the crumble, first knead the flour, butter, sugar, and vanilla sugar with the dough hook of a mixer and then knead or rub together with your hands. Chill. For the dough, cream the butter and sugar until creamy. Beat in the eggs one at a time for about half a minute, then add the vanilla extract and/or tonka bean zest. Mix the flour with the baking powder and baking soda and briefly stir in alternately with the buttermilk. Pour the batter into a greased or lined 26 cm springform pan and smooth the surface. Then sprinkle with the washed and dried blueberries. (Frozen blueberries can be used frozen.) Spread the crumble on top. Bake in a preheated oven at 175°C (350°F) on the bottom rack for about 50-60 minutes. Allow to cool, ideally overnight; this is when the cake tastes best! Dust with powdered sugar before serving. If you like, you can also serve with whipped cream.