Prepare the Cookie Base

1. In a large pot, combine butter, sugar, cocoa powder, and milk over medium-high heat.
2. Stir frequently until the mixture reaches a boil. Allow it to boil for 1-2 minutes.
3. Remove from heat and stir in vanilla extract and salt.
4. Add the quick oats and shredded coconut to the pot, mixing until well combined.
5. Spoon the mixture onto lined baking sheets, forming 24 evenly sized mounds.
6. Refrigerate the cookies until firm, about 30 minutes.

2. Make the Mint Frosting

1. In a mixing bowl, beat the butter until smooth and creamy.
2. Gradually add the icing sugar and milk, mixing until smooth.
3. Stir in mint extract and green food coloring, adjusting the color as desired.
4. Spread a generous layer of frosting onto each chilled cookie and return to the refrigerator to set.

3. Prepare the Chocolate Ganache

1. Combine chocolate chips, milk, and butter in a small saucepan over low heat.
2. Stir constantly until the chocolate melts and the mixture is smooth. Remove from heat and let cool for 5-10 minutes.

4. Assemble the Cookies

1. Spread a layer of ganache over the frosting on each cookie.
2. Return the cookies to the refrigerator for a final chill, allowing the ganache to set completely.