Preheat your oven to 350 degrees. Spray an 9 inch square pan with non-stick spray.
Combine blueberries, 1 cup sugar, and cinnamon in a medium saucepan. Bring to a slow boil.
Dissolve the corn starch in 1/2 cup water. Stir into your blueberry mixture and cook until somewhat thickened. Pour into your prepared pan.
Combine flour, 1 tablespoon sugar, baking powder, and 1/2 cup butter in a strong blender or food processor. Pulse until butter is pea sized. Add the milk and blend until your dough forms.
Drop the dough by the tablespoon full onto the top of your blueberry base. Spread with 1-2 tablespoons of melted butter and sprinkle with 1 tablespoon of sugar.
Bake 30 minutes or until lightly browned.