Blueberry Crumble Slice

Ingredients:

Crumble base and topping:

360g/12.75oz plain flour
1 tsp baking powder
230g/8oz cold butter, cut into small cubes
120g/4oz white sugar
120g/4oz light brown sugar
½ tsp salt
1 large egg, beaten
1 tsp vanilla extract

Blueberry Filling:

450g/16oz blueberries
120g/4oz white sugar
2 tsp lemon juice
3 tsp cornstarch

Directions: