01 - Preheat the oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together the flour, baking powder, and salt until well blended.
03 - In a large bowl, beat the butter and sugar together using an electric mixer until light and fluffy, approximately 2-3 minutes.
04 - Add the egg, vanilla extract, and almond extract. Mix until fully incorporated and smooth.
05 - Gradually add the flour mixture to the wet ingredients, mixing just until the dough comes together. Do not overmix.
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. Place them 2 inches apart on the prepared baking sheets.
08 - Gently flatten each dough ball slightly with the palm of your hand to ensure even baking.
09 - Bake for 10-12 minutes, or until the edges are set but the centers remain slightly soft. Take care not to overbake.
10 - Let the cookies cool on the baking trays for 5 minutes, then transfer them to a wire rack to cool completely.
11 - Beat the butter until creamy. Add the powdered sugar, vanilla extract, salt, and milk. Beat until smooth and fluffy. Adjust consistency with additional milk if needed.
12 - Once the cookies have cooled completely, pipe or spread a layer of buttercream onto the flat side of half the cookies. Top each with a matching colored cookie to form sandwiches.
13 - Press sprinkles into the exposed buttercream edges if desired. Serve immediately or store in an airtight container.