Preheat the oven to 350 degrees. Line an 8-inch square baking pan with aluminum foil and grease foil with either butter or vegetable shortening. Melt the cannabutter and chocolate together in a small saucepan over low heat, stirring frequently until smooth. Let cool for 5 minutes.
Stir together the flour salt, and cocoa powder together, set aside.
Beat the sugar and brown sugar into the chocolate mixture. Beat the eggs in until well incorporated. Stir in the flour mixture until just incorporated and pour batter into the prepared pan.
Bake for about 25 to 30 minutes or until a toothpick inserted in the center comes out with just a few moist crumbs clinging to it. Let cool completely before proceeding.
Prepare Mint Buttercream Layer:
use an electric mixer to beat the butter until fluffy. Beat in the confectioner’s sugar extract, milk and food coloring.
Once brownies are completely cool, spread the mint buttercream in an even layer over the brownies in the pan and return to fridge to chill for at least an hour.
Prepare Chocolate Glaze:
Melt butter and chocolate chips together in a small saucepan over low heat, stirring until smooth. Cool slightly and pour over chilled brownies, using an offset spatula or butter knife to spread until you have a smooth even layer. Chill for at least another hour before slicing.
Use the foil to lift out the brownies out of the pan. For best presentation, use a sharp knife to slice, and wipe off the knife between cuts.