Mix first 7 ingredients and reserve 1 cup for topping.
Add the last 5 ingredients and mix together until combined, but not smooth. The mixture may be lumpy.
Pour mixture into a well buttered 9 x 12 pan and add the reserved cup of topping.
Bake in preheated 375 degree oven for 25-30 minutes or until a toothpick comes out mostly clean (a few dry crumbs are ok).
Let cool for 10 minutes.