Preheat the Oven and Prepare the Baking Sheet:
Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper or lightly grease it.
Mix the Dry Ingredients:
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
Cream the Butter and Sugar:
In a large bowl, use an electric mixer to cream together the softened butter and sugar until light and fluffy, about 3 minutes.
Add the Egg and Vanilla:
Beat in the egg and vanilla extract until fully combined.
Add Dry Ingredients to Wet Ingredients:
Gradually add the dry ingredients to the wet ingredients, mixing just until incorporated. If the dough is too thick, add 2 tablespoons of milk to help bring it together.
Shape the Cookies:
Scoop the dough into tablespoon-sized portions and roll into balls. Place the dough balls on the prepared baking sheet about 2 inches apart.
Flatten each dough ball slightly with the back of a spoon or your fingers.
Bake the Cookies:
Bake for 8-10 minutes, or until the edges are just starting to turn golden. The cookies should remain soft in the center.
Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.
Make the Strawberry Frosting:
In a medium bowl, beat the softened butter until smooth. Gradually add the powdered sugar, a little at a time, until fully combined.
Add the strawberry puree (or extract), milk, and pink food coloring (if desired), and beat until the frosting is smooth and fluffy.
Frost the Cookies:
Once the cookies have cooled completely, spread the strawberry frosting generously on each cookie using a spatula.
Add sprinkles or additional decorations on top of the frosting for extra flair.