1. Preheat the oven to 350°. Combine first 4 ingredients; stir batter by hand, mixing well. Press half of peanut butter mixture onto bottom of an ungreased 9" x 13" pan.
2. Bake at 350° for 10 minutes. Remove from oven; sprinkle with peanut butter morsels, and drizzle with condensed milk. Sprinkle with remaining peanut butter mixture.
3. Bake 30 more minutes. Cool completely, and cut into bars.
Chocolate Peanut Butter Bars: Substitute chocolate cake mix for yellow cake mix.