2 (6 ounce) packages butterscotch chips
1 cup peanut butter
1/2 cup butter
1 package miniature marshmallows, divided
Mix butterscotch chips, butter and peanut butter together in the top of a double boiler. Heat and stir until melted. Add half the marshmallows and stir until melted. Remove from heat and allow to cool about 10 minutes.
Stir in remaining marshmallows after the mixture has cooled down enough that the marshmallows will not melt. Spread into a 9 x 13-inch pan and chill. Cut into small squares.