01 - In a medium bowl, whisk together the flour, baking powder, and salt until fully blended. Set aside.
02 - Beat the softened butter with the granulated sugar in a large bowl using a hand or stand mixer on medium speed for 2 to 3 minutes, until pale and fluffy.
03 - Add the egg and vanilla extract to the creamed mixture, beating until fully combined.
04 - Gradually add the flour mixture to the wet ingredients, mixing on low speed just until a dough forms.
05 - Divide the dough evenly into two portions. Flatten each into a disc, wrap securely in plastic wrap, and refrigerate for at least 30 minutes.
06 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
07 - On a lightly floured work surface, roll out one disc of dough to a 1/4-inch thickness. Use a 2-inch round cookie cutter to cut circles.
08 - Arrange cookies 2 inches apart on prepared baking sheets. Bake for 10 to 12 minutes, until edges are just turning golden.
09 - Allow cookies to cool on baking sheets for 5 minutes, then transfer to a wire rack to cool completely.
10 - In a small bowl, whisk powdered sugar with 2 teaspoons of milk and vanilla until smooth and thick but spreadable. If needed, add extra milk a drop at a time to reach desired consistency. Tint with food coloring as preferred.
11 - Spread or pipe icing onto the cooled cookies. Immediately place edible googly eyes onto icing before it sets.
12 - Allow decorated cookies to sit until icing is fully set before storing or serving.