Blueberry Pudding Cake

2 cups fresh or frozen blueberries (no need to thaw)
1 teaspoon ground cinnamon
1 teaspoon lemon juice
1 cup all-purpose flour
3/4 cup sugar
1 teaspoon baking powder
1/2 cup milk
3 Tablespoons butter or margarine -- melted
Topping:
3/4 cup sugar
1 Tablespoon cornstarch
1 cup boiling water

Toss the blueberries with cinnamon and lemon juice; place in a greased 8 inch square baking dish.In a bowl, combine flour, sugar, and baking powder; stir in milk and butter. Spoon over berries.Combine sugar and cornstarch; sprinkle over batter. Slowly pour boiling water over all.Bake at 350 degrees for 45-50 minutes or until cake is golden and tests done.Cool a bit and serve warm with vanilla ice cream.