Preheat oven to 350 F.
Grease a 13x8 inch jelly roll pan.
In a large bowl, cream together sugars and butter.
Add vanilla, eggs, and 1 cup peanut butter and mix well.
Stir in oats, flour, baking soda, and salt.
Spread dough on prepared pan and bake 15 minutes until golden brown.
While hot, spread remaining 1½ cups peanut butter on top. (Fred’s note: works better to melt pb in microwave and pour/spread on top.)
Cool so that the peanut butter solidifies again. (I usually chill them in the fridge so they set up faster and we can eat these bad boys sooner!)
Spread Mom's Chocolate Frosting on top.
Cut into bars when ready to serve.