1 c. peanut butter
1/2 c. corn syrup
1/2 c. brown sugar
1 tsp. vanilla extract
3 c. Rice Krispies

Combine peanut butter, corn syrup, brown sugar and vanilla extract in a saucepan. Place over low heat and stir until melted and thoroughly combined. Remove from heat and stir in cereal until completely coated with peanut butter mixture.

Press into lightly greased 8 inch square pan. Chill 1 hour; then frost by melting 1 cup chocolate chips and 1 tablespoon butter together. Spread over chilled squares while frosting is still hot. Keep in refrigerator.