Preheat oven to 350 degrees.
Grease bottom of a 9 x 13 inch pan.
Prepare brownie mix as directed on package.
Spread batter into pan. Bake 24 - 27 minutes.
Remove from oven and top with marshmallow, chocolate chips, m&m's, toffee, and drizzle with caramel.
Bake 1 - 2 minutes more until marshmallows are puffy.
Cool in pan on wire rack.