Pre-heat the oven at 350°F.
In a mixing bowl, using an electric mixer, beat all the ingredients, except the blueberries, together, at medium speed until the mixture is well-mixed and creamy, about 2 minutes.
Fold in the blueberries
Spread the mixture in a 9x12" rectangular pan.
In a small bowl, thouroughly blend the Crumb Mixture ingredients.
Bake at 350°F for 50 minutes or until a cake tester comes out of the center
Best served when still warm, with ice cream or whipped cream when desired.
Ann Shewman Gerrish