Marshmallow Peanut Butter Squares

1 cup creamy peanut butter
1/2 cup butter
2 (6 ounce) packages butterscotch chips
1 large package miniature colored marshmallows

Put the peanut butter, butter and butterscotch chips in a heavy-bottomed saucepan and cook over low heat until melted and well combined. Let cool.

Add marshmallows, and put into a buttered 8-inch square pan. Store in refrigerator.