In a saucepan mix cornstarch, sugar, and water. Add berries and cook on medium to medium high heat until mixture is thickened, about 15 minutes. Add butter and lemon juice. Pour into an 8" baking dish.
Prepare the batter by mixing all of the batter ingredients and beating with a spoon until the batter is smooth.
Drop the batter over the berry mixture. Bake 25-30 minutes at 350°F.