In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add the dry ingredients to the wet mixture, mixing until just combined.

Wrap the dough in plastic wrap and refrigerate for at least 30 minutes.

Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper.

On a floured surface, roll out the chilled dough to about 1/4 inch thick. Use a butterfly-shaped cookie cutter to cut out cookies.

Place the cookies on the prepared baking sheet and bake for 12-15 minutes or until the edges are lightly golden.

Remove from the oven and let cool completely on a wire rack.

In a small bowl, mix the powdered sugar and milk to create a smooth icing. Add food coloring if desired.

Use the icing to decorate the cooled cookies as desired.