• Line an 8x8 square baking dish with parchment paper, set aside.

For the Bottom Layer:

• Combine butter, sugar, and cocoa in a large saucepan over low heat. Stir frequently until butter is melted and sugar and cocoa are dissolved. Remove from heat.
• Temper the egg by taking a few spoonfuls of the chocolate mixture and whisking it into the egg. Add the egg and vanilla to the remaining chocolate mixture in the saucepan, whisking quickly until egg is well-incorporated. Don't worry if the chocolate starts to seize up, just stop stirring when egg is mixed in.
• Add in the coconut, graham cracker crumbs, and pecans. Stir until all is coated in chocolate.
• Dump out mixture into prepared pan and press down firmly using damp hands to form a crust. Place in fridge while preparing middle layer.

For the Middle Layer:

• In a stand mixer, cream butter on medium speed until smooth and pale yellow.
• Add in confectioner's sugar, one cup at a time, until well combined.
• Add milk and mix on medium until mixture is smooth. Add in vanilla pudding or custard powder and peppermint extract. Mix until smooth. Add in chocolate chips and food coloring (if using) and mix until evenly distributed.
• Spread middle layer on top of chilled bottom later evenly using a spatula. Place in fridge while preparing last layer.

For the Top Layer:

• In a double broiler (or a heatproof bowl over 1" of simmering water in a saucepan) melt butter and chocolate squares until smooth. Remove from heat.
• Pour chocolate and butter mixture over top of middle layer and spread with a spatula. Return bars to fridge to cool completely. After cooled, use a sharp knife to cut into small squares.