Brownies with Chocolate Mint Frosting

I got this recipe from my MIL. She uses the frosting for both Texas Sheet Cake and brownies. We made this for a play group outing and then while I was with my family in CA. I added the chocolate chips and mint extract to the brownies. It kind of reminds me of the BYU mint brownies.

1 brownie mix (plus required ingredients - usually water, oil and eggs)
1 c. semi-sweet chocolate chips
1/2 tsp. mint extract

Mix brownies according to package directions, then add chocolate chips and mint extract. Bake according to package directions for a 9x13 pan. Let cool completely.

Mint filling
1/2 c. butter
2 c. powdered sugar
1/2 tsp. mint extract
1 Tbsp.water
1 tsp. vanilla
3 drops green food coloring
Beat together butter and powdered sugar until smooth. Add remaining ingredients and beat until smooth and spreadable. Spread over cooled brownies. Refrigerate until set.

Chocolate topping
1 12 oz pkg. semi-sweet chocolate chips
9 Tbsp. butter
Melt chocolate chips and butter in saucepan over low heat, stirring constantly. Let cool for 30 minutes, stirring occasionally. Spread over filling. Chill in fridge until set. Cut into squares - enjoy!