01 - Whisk together flour, baking powder, and salt in a medium bowl until well combined.
02 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 2-3 minutes.
03 - Mix in egg, vanilla extract, and almond extract until fully incorporated into the butter mixture.
04 - Gradually add dry ingredients to wet ingredients, mixing on low speed just until dough comes together. Avoid overmixing.
05 - Divide dough in half, shape into disks, and wrap each tightly in plastic wrap. Refrigerate for at least 1 hour.
06 - Preheat oven to 350°F and line baking sheets with parchment paper.
07 - On a lightly floured surface, roll dough to ¼-inch thickness. Cut shamrock or round shapes and place 1 inch apart on prepared sheets.
08 - Bake for 8-10 minutes until edges begin turning golden. Let cool on baking sheet for 2 minutes, then transfer to wire rack.
09 - Whisk powdered sugar, milk, and vanilla extract until smooth. Add green food coloring to achieve desired shade.
10 - Decorate completely cooled cookies with green icing and sprinkles. Allow icing to set before serving.