Preheat your oven to 350°F (175°C). Line a 9x9 inch square baking pan with parchment paper, leaving an overhang on the sides so you can easily lift the bars out later.
In the bowl of a stand mixer, cream the softened butter and granulated sugar on medium-high speed until light and fluffy (about 2-3 minutes).
Beat in the room-temperature egg, vanilla extract, and almond extract until well combined and smooth.
Turn the mixer to low speed and add the all-purpose flour, baking powder, and salt. Mix just until the dry ingredients are incorporated. Do not overmix.
Transfer the thick dough to the prepared baking pan. Use lightly floured hands or a rubber spatula to press the dough evenly across the bottom of the pan.
Bake for 15-18 minutes, or until the edges are lightly golden brown but the center remains slightly soft.
Allow the cookie block to cool completely in the pan on a wire rack.
To make the frosting: In a clean bowl, beat the softened butter on medium-high speed for 2 minutes until very creamy.
Gradually add the powdered sugar, 1 tablespoon of milk, vanilla extract, and a drop of pink food coloring. If the frosting is too thick, add the second tablespoon of milk.
Beat the frosting on high speed for 3 full minutes until it is light, fluffy, and smooth.
Once the cookie block is 100% cooled, use an offset spatula to spread the buttercream evenly over the top. Immediately decorate with holiday sprinkles.
Use the parchment paper overhang to lift the bars onto a cutting board. Slice into 16 even squares and serve.