1 (12 oz.) pkg. chocolate chips
1 stick butter
1/2 c. corn syrup
1 c. powdered sugar
2 tsp. vanilla
4 c. Rice Krispies

Cook first 3 ingredients over low heat until smooth, then remove from heat. Add 1 cup powdered sugar, vanilla and Rice Krispies. Put in well greased pan and cool in refrigerator until firm.