01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper and set aside.
02 - In a medium bowl, whisk together the flour, baking powder, and salt until well combined.
03 - In a large bowl, beat the butter and sugar together until light and fluffy, approximately 2-3 minutes.
04 - Add the egg, vanilla extract, and almond extract to the butter mixture, mixing until fully incorporated.
05 - Gradually add the flour mixture to the wet ingredients, mixing just until the dough comes together and no dry streaks remain.
06 - Divide the dough evenly into 4-5 separate bowls. Add a different pastel gel food coloring to each bowl, mixing thoroughly until the color is uniform throughout.
07 - Using a tablespoon or cookie scoop, portion the dough into balls and place them 2 inches apart on the prepared baking sheets.
08 - Gently flatten each dough ball with the palm of your hand to ensure even baking.
09 - Bake for 10-12 minutes, or until the edges are set while centers remain slightly soft. Take care not to overbake.
10 - Allow the cookies to cool on the baking trays for 5 minutes, then transfer to a wire rack to cool completely before filling.
11 - Beat the softened butter until creamy. Add the powdered sugar, vanilla extract, salt, and milk. Beat until smooth and fluffy, adding additional milk if needed to achieve spreadable consistency.
12 - Once the cookies have cooled completely, pipe or spread a generous layer of buttercream onto the flat side of half the cookies. Top each filled cookie with a matching cookie to form sandwiches.
13 - Press sprinkles into the exposed buttercream edges around each sandwich cookie for decoration, if desired.