Chocolate Oatrage Snack Cake

Yield:	12 Servings
Categories:	Microwave, Cakes

1	c	Butter or margarine; soft
1 1/2	c	Oatmeal; quick -OR- Old fashioned, uncooked
1/2	c	All-purpose flour
1	c	Brown sugar; firmly packed
2		Eggs
1	c	Walnuts; chopped
1	ts	Vanilla
12	oz	Semi-sweet chocolate chips: divided