Preheat the oven to 350°F.
Melt the butter and unsweetened baking chocolate in a saucepan over low heat, stirring until smooth. Set aside to cool.
In a large mixing bowl, beat the eggs and sugar on medium speed for 8 minutes. Add the cooled cocoa butter mixture, vanilla, and salt. Mix until well combined.
In a separate bowl, combine the flour and baking powder. Gradually add the dry ingredients to the wet mixture, spooning them in at a time on low speed. Beat until just combined.
Pour the batter into the prepared 9x13 pan. Bake for 20-30 minutes or until the edges are set and a toothpick inserted into the center comes out clean. Let cool.
After cooling, place the brownies in the freezer for about 30 minutes.
In a mixing bowl, beat the powdered sugar, softened butter, peppermint extract, green food coloring, and milk until smooth and fluffy. Spread the frosting evenly over the frozen brownies.
Melt the semi-sweet chocolate chips and 4 TBS of butter together. Pour the glaze over the frosted brownies, tipping and tapping the pan until fully covered. Freeze again.
After freezing, remove the brownies from the pan and cut into squares.
