01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, and salt until well blended.
03 - In a large bowl, beat 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 mixture.
05 - Gradually add dry ingredients to wet ingredients, mixing until dough just comes together. Avoid overmixing.
06 - Divide dough in half, flatten into disks, wrap tightly in plastic wrap, and refrigerate for 30 minutes.
07 - On a lightly floured surface, roll dough to 1/4-inch thickness. Cut cookies using round or flower-shaped cutters.
08 - Arrange cookies 2 inches apart on prepared baking sheets. Bake for 10-12 minutes until edges are lightly golden.
09 - Let cookies rest on baking sheets for 5 minutes, then transfer to wire rack to cool completely before decorating.
10 - Beat butter until smooth and creamy. Gradually incorporate sifted confectioners sugar, mixing thoroughly after each addition.
11 - Add milk, vanilla, and salt. Beat for 2-3 minutes until light and fluffy. Adjust consistency with additional milk if needed.
12 - Divide buttercream among separate bowls. Tint each portion with gel food coloring to achieve desired shades.
13 - Fit piping bags with small star, petal, and leaf tips. Fill bags with different colored buttercreams.
14 - Pipe flowers and decorative leaves onto completely cooled cookies using prepared tips and colored buttercream.
15 - Allow decorated cookies to rest at room temperature until buttercream firms slightly before serving or packaging.