Preheat the Oven: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

Mix the Dough: In a large bowl, combine the box cake mix, eggs, vegetable oil, vanilla extract, green food coloring and peppermint extract. Stir until a soft dough forms.

Shape the Cookies: Using a tablespoon, scoop the dough onto the prepared baking sheet, spacing them about 2 inches apart.

Bake: Bake in the preheated oven for 10-12 minutes or until the edges are set. Remove from the oven and let them cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.

Prepare the Frosting: In a mixing bowl, beat together the powdered sugar, softened butter, and Baileys Irish Cream Liqueur until smooth and creamy.

Frost the Cookies: Once the cookies are completely cool, spread a generous layer of the Irish cream frosting on top.

Add Toppings: Carefully place a rainbow candy strip and a Lucky Charms shamrock marshmallow on top of each frosted cookie for decoration.

Serve: Enjoy your Shamrock Shake Cake Mix Cookies with friends or family, and share the festive spirit!