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 until light and fluffy, about 2-3 minutes.
04 - Add the egg, vanilla extract, and almond extract, mixing until fully combined.
05 - Gradually add the flour mixture to the wet ingredients, mixing just until incorporated. Do not overmix.
06 - Divide the dough evenly into 4-5 bowls. Tint each bowl with a different pastel gel food coloring, mixing until color is uniform throughout.
07 - Using a tablespoon or cookie scoop, portion dough into balls and place 2 inches apart on prepared baking sheets.
08 - Flatten each ball slightly with your palm to ensure even baking.
09 - Bake for 10-12 minutes, or until edges are set but centers are still soft. Do not overbake.
10 - Cool cookies on the trays for 5 minutes, then transfer to a wire rack to cool completely before filling.
11 - Beat the butter until creamy. Add powdered sugar, vanilla, salt, and milk. Beat until smooth and fluffy. Add more milk if needed for spreadable consistency.
12 - Once cookies are completely cool, pipe or spread buttercream onto the flat side of half the cookies. Top each with a matching cookie to form sandwiches.
13 - Press sprinkles into the exposed buttercream edges if desired for a festive finish.