Prepare Brownie mix according to package directions. Pour into a greased 16x10" baking pan. Bake at 350 Deg F. for 25-30 min or until inserted knife comes out clean. Cool on a wire rack.
In a bowl combine the (non topping) frosting ingredients until smooth. Spread over the cooled brownies.
Topping:
Melt chips and butter. Stir in the extract. Spread over the frosting. Allow to harden before cutting.
Original recipie makes 32 bars in one 16x10" pan.
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Mint Chocolate Brownies recipe