BASE:

1 pkg. yellow cake mix
3/4 c. quick-cook oatmeal
1/2 c. softened butter
1/4 c. peanut butter
1 egg

FROSTING:

1 can ready to spread frosting
1/4 c. peanut butter
1/2 c. chopped nuts (opt.)

Combine base ingredients in large bowl and mix until crumbly. Press mixture in 9 x 13 inch pan. Bake at 350 degrees for 10 to 20 minutes. When cooled, spread icing and sprinkle with chopped nuts, if desired.