Combine dry ingredients: flour, baking powder, and salt in a large bowl. Set it aside.
In another medium bowl, mix butter and sugar until smooth.
Add egg and milk.
On low speed, gradually add flour to the mixer until it separates from the bowl.
Knead the dough until mixed well.
If you want to add food coloring, knead it into the dough until it spreads evenly.
Shape the dough into a log, wrap it in plastic wrap, and cool it in the fridge for 2 hours.
Cut the dough into cookies and bake cookies at 375℉ degrees for 7-10 minutes on a baking sheet lined with wax paper or parchment paper.
Let the cookies cool on a wire cooling rack and then frost them with white icing.
Use chocolate icing or royal icing to write messages on the baked cookies. Cut a small hole in the corner of a piping bag or a plastic bag for this.
Put a heart sprinkle on each cookie.
Notes
For best results, make sure that your butter is at room temperature. This will help you get the fluffiest and softest Valentines day homemade cookies.
Do not overmix your cookie dough once you add in the flour. The best way is to mix until just combined once you add the flour. Overmixing the flour will cause your cookies to be tough.
Be sure to chill your cookie dough before baking so that the cookies hold their shape well during the baking process.
If you do not have a piping bag on hand, you can use a storage bag with a corner cut-off.