Preheat oven to 350.Grease a 9×13 inch pan with nonstick cooking spray.I don’t use nonstick cooking spray–I use my butter wrappers to grease the pan.
Add the butter and the unsweetened chocolate (chopped into chunks) and place together in a microwave safe bowl.Microwave on low power in 30 second intervals, stirring inbetween, until melted.Set aside and cool, stirring occasionally.
In a large bowl, beat together the eggs, granulated sugar, and vanilla.Slowly add the melted chocolate, while mixing.In a separate small bowl whisk together the flour and baking powder.Stir the flour mixture into the chocolate batter, just until combined.Don’t over mix.
Pour batter into greased pan and bake for 20 to 30 minutes or until a toothpick inserted in the center comes out clean.Remove from oven and cool.
For the filling, mix the butter until nice and fluffing.Add the powdered sugar, milk, peppermint extract, and food coloring and mix until nice and creamy.
Spread over the cooled brownies.Place in the refrigerator while preparing the ganache.
For the ganache, heat the cream and butter until just barely simmering.Pour over the chocolate chips and stir until smooth and glossy.Stir in the mint extract.
Spread the ganache evenly over the mint layer.Refrigerate for an hour or so or until the chocolate layer has set.
Cut into squares and serve.Store in an airtight container in the refrigerator.