01 - Preheat oven to 350°F and line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, and salt until evenly distributed.
03 - In a large bowl, beat softened butter and granulated sugar together until light and fluffy, approximately 2–3 minutes.
04 - Beat in the egg and vanilla extract until fully incorporated into the butter mixture.
05 - Gradually add the dry ingredients to the wet mixture, mixing just until a cohesive dough forms.
06 - Divide dough in half, flatten into disks, wrap tightly in plastic, and refrigerate for 30 minutes.
07 - On a lightly floured surface, roll dough to 1/4-inch thickness. Cut out cookies using round or flower-shaped cutters.
08 - Place cookies 2 inches apart on prepared baking sheets. Bake for 10–12 minutes, until edges are just turning golden.
09 - Let cookies rest on baking sheet for 5 minutes, then transfer to a wire rack to cool completely before decorating.
10 - Beat softened butter until smooth and creamy. Gradually add sifted confectioners sugar, mixing thoroughly after each addition.
11 - Add milk, vanilla, and salt. Beat for 2–3 minutes until light and fluffy. Add additional milk 1 teaspoon at a time if needed for piping consistency.
12 - Divide buttercream into separate bowls and tint with gel food coloring to achieve desired shades.
13 - Fit piping bags with small star, petal, and leaf tips. Fill each bag with a different colored buttercream.
14 - Pipe decorative flowers and leaves onto completely cooled cookies using various tips for different effects.
15 - Allow decorated cookies to rest at room temperature until buttercream firms slightly before serving or storing.