Blueberry Dump Cake

1 (18.25 ounce) box yellow cake mix
4 cups fresh blueberries, or thawed
1/2 cup granulated sugar
1/2 cup butter or margarine, melted
1 teaspoon ground cinnamon

Preheat oven to 350 degrees F.

Mix blueberries, sugar and cinnamon in the bottom of a 13 x 9-inch pan. Cover blueberries with dry cake mix. Pour butter over cake mix, but do not stir.

Bake for 30 minutes or until light brown. Serve warm or cold, topped with ice cream.