Blueberry Pudding Cake

2 cups fresh or frozen blueberries
1 tsp ground cinnamon
1 tsp lemon juice
1 cup all-purpose flour
3/4 cup sugar
1 tsp baking powder
1/2 cup milk
3 Tbsp butter or margarine, melted
Topping:
3/4 cup sugar
1 Tbsp 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 tests done.