01 -
Set oven to 350°F (175°C) and line two baking sheets with parchment paper.
02 -
In a mixing bowl, cream together 1/2 cup unsalted butter and 1 cup granulated sugar until light and fluffy. Beat in the egg and vanilla extract until fully combined.
03 -
In a separate bowl, whisk together the all-purpose flour, cocoa powder, baking soda, and salt.
04 -
Gradually add the dry ingredients to the creamed butter mixture, mixing until a uniform dough forms.
05 -
Portion dough into even balls using a cookie scoop and place them spaced apart on prepared baking sheets. Bake for approximately 10 minutes, until the edges are set and centers appear slightly soft.
06 -
Remove cookies from the oven and allow to cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.
07 -
In a clean bowl, beat 1/4 cup unsalted butter until creamy. Gradually add powdered sugar and milk, beating until smooth. Mix in mint extract to taste, and add green food coloring if using.
08 -
Spread or pipe a layer of mint frosting over each cooled cookie.
09 -
Melt chocolate chips with oil in a heatproof bowl set over a pan of simmering water, or microwave in short bursts, stirring until smooth.
10 -
Drizzle melted chocolate ganache over frosted cookies. Allow ganache to set before serving or storing.