This decadent treat combines the best of three favorite indulgences--Mississippi Mud cake, Rocky Road ice cream and Turtle candy. Cleanup is easy. In fact, the most difficult part will be waiting for them to cool in the refrigerator. Well, that and limiting yourself to just one.
Preheat oven to 350 degrees F. Line 8" x 8" baking pan with foil, leaving an overhanging edge for easier brownie removal. Grease foil.
Prepare brownie mix according to package directions. Add pecans, if desired, and mix well. Bake for 37 minutes. Remove from oven. Soften caramel in microwave-safe bowl and pour over hot brownies. Add dollops of marshmallow cream, carefully spreading to cover brownies. Top with marshmallows. Return brownies to oven and bake for an additional 5 minutes. If marshmallows require further browning, place under broiler on lower rack until golden brown.
While the brownies are finishing, melt chocolate chips in double boiler or microwave oven; stir. Add butter and stir until melted. Continue stirring periodically until chocolate and butter are smooth and shiny.
Remove brownies from oven and cool slightly before spreading chocolate over top. Cool completely in refrigerator for a minimum of 3-4 hours to allow marshmallow layer to set. Cut into squares.