Combine all ingredients, except chocolate chips in a medium sized bowl. Stir until the mixture is smooth and creamy. If it's too soft add a little more powdered sugar. Press into the pan and place in the refrigerator.
Melt chocolate chips in the microwave (at 50% power) for 1-2 minutes or cook on the stove over a double broiler. Stir chocolate and pour over the peanut butter mixture. Spread chocolate with a spatula. To even out chocolate, tap pan on the counter.
Refrigerate bars until chocolate has hardened (about 30 minutes- 1 hour) or place in the freezer to make the cooling time faster. Cut while bars are still cool. Enjoy!
These are best kept stored in the refrigerator or freezer.