Add the vanilla, eggs, and peanut butter and combine.
Add the remaining ingredients and mix together.
Spread dough on a greased jelly roll pan (18x13x1").
Bake at 350 degrees for 15 minutes (until golden brown).
While hot spread 1½ cups peanut butter on top. Cool so that the peanut butter has become solid again. You can put them in the fridge so they set up faster.
Mix frosting ingredients with a hand mixer until smooth and spread on top of bars.
Cut into squares.
Recipe by Mandy's Recipe Box at https://mandysrecipeboxblog.com/lunch-lady-peanut-butter-bars/