01 -
Preheat oven to 375°F. Spray 9"x13" baking pan with nonstick spray and line bottom with parchment paper.
02 -
Combine melted butter, flour, baking powder, cinnamon, sugar and brown sugar. Add eggs and almond extract; stir well.
03 -
Reserve 1½ cups of mixture for topping. Press remaining mixture into prepared pan.
04 -
Whisk together sugar, lemon juice and cornstarch. Gently stir in blackberries and spread over base.
05 -
Sprinkle reserved crumble mixture on top. Bake 40-45 minutes until golden brown. Cool completely before slicing.