1 c. peanut butter chips
2 c. milk chocolate chips
1 can sweetened condensed milk
1/4 c. butter
1 c. chopped walnuts (optional)

1. Place all ingredients except nuts in large bowl.

2. Microwave at medium until chocolate chips are melted, 3 to 5 minutes, stirring once or twice during cooking. Stir in nuts. Pour into well greased square baking dish 8x8 inches.

3. Refrigerate.