Step 1: In a large mixing bowl, combine peanut butter and butter -- mix 30 seconds at medium speed. Add sugars and beat until fluffy. Add egg and vanilla and beat well.
Step 2: Add flour, baking soda and baking powder in a separate bowl and whisk to combine. Add dry ingredients to wet ingredients and mix to combine. With wooden spoon, stir in oatmeal and chocolate chips.
Step 3: Drop dough by 1/4 cupfuls onto cookie sheet about 3" apart. Press into 4" circles. Bake at 375 degrees Fahrenheit for 10 minutes.
Step 4: Cool on wire rack.