Creating Irish Mint Brownies can be a fun and straightforward process using these steps:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and line a 9×13-inch baking pan with parchment paper for easy removal.

2. Melt the Butter: In a medium saucepan over low heat, melt the butter completely. Remove from heat and stir in the granulated sugar until well combined.

3. Add Eggs and Vanilla: Let the mixture cool slightly, then whisk in the eggs, one at a time, along with the vanilla extract until smooth.

4. Mix Dry Ingredients: In another bowl, whisk together the flour, cocoa powder, baking powder, and salt.

5. Combine Mixtures: Gradually fold the dry ingredients into the wet mixture. Stir until no streaks remain and the batter is smooth.

6. Bake the Brownies: Pour the brownie batter into the prepared pan and spread evenly. Bake in the preheated oven for 25-30 minutes or until a toothpick inserted in the center comes out clean.

7. Cool the Brownies: Remove the brownies from the oven and let them cool in the pan for about 10-15 minutes before transferring to a wire rack to cool completely.

8. Prepare the Mint Frosting: In a mixing bowl, beat the softened butter until creamy. Gradually add the powdered sugar, alternating with milk, and mix until light and fluffy. Stir in the peppermint extract and green food coloring if desired.

9. Frost the Brownies: Once the brownies are completely cool, spread the mint frosting evenly on top.

10. Make the Ganache: In a small saucepan, heat the heavy cream until it begins to simmer. Pour it over the chopped chocolate in a bowl, letting it sit for a couple of minutes before stirring until smooth.

11. Top with Ganache: Drizzle the chocolate ganache over the mint frosting, adding an elegant finish to the brownies.

12. Chill: Allow the brownies to set in the refrigerator for about 30 minutes before slicing into squares for serving.