Blueberry Sour Cream Cake

• 125 grams softened butter
• 1 egg
• 1/2 cup sugar
• 1 1/2 cups flour
• 1 1/2 tsp baking powder
• 3 cups blueberries
• 2 cups sour cream
• 2 egg yolks
• 1/2 cup sugar
• 1 tsp vanilla

1. Combine butter, egg, sugar, flour and baking powder and spread into a tim.
2. Spread blueberries over base
3. Combine sour crea, egg yolks, sugar and vanilla and pour over the berries. 
4. Bake at 180 degrees celsius for abou an hour - until custard topping is firm