S'more Cookie Bars

I know there's lots of different S'More bar recipes out there, but I couldn't find this one listed and want to try it soon! (This was taken from the back of an Imperial margarine package)

• Ready In: 35 mins
• Serves: 24
• Yields: 24 squares

Ingredients

• 3⁄4 cup margarine or 3⁄4 cup butter
• 3  cups graham cracker crumbs (wafer)
• 1 (6 ounce) package  semi-sweet chocolate chips (1 cup)
• 1  cup  butterscotch chips
• 1  cup mini marshmallows
• 1 (14 ounce) can sweetened condensed milk

Directions

1. Preheat oven to 350 degrees F.
2. In 13" x 9" baking pan, combine margarine with crumbs; press to form even layer.
3. Evenly sprinkle with chocolate chips, then butterscotch chips, then mini marshmallows.
4. Pour condensed milk evenly over mixture.
5. Bake 25 minutes or until bubbly.
6. On wire rack, let cool completely.
7. Cut into squares. (For easier cutting, refrigerate for 1 hour).