In a medium bowl, simply whisk together your all-purpose flour and baking powder until well combined. Set this aside for a moment.
Grab an electric mixer and beat the melted butter until it becomes light and fluffy. Then, add in the eggs, granulated sugar, and almond extract. Continue mixing until all these wet ingredients are beautifully combined. Don't worry if the mixture looks a little chunky at this stage!
Gradually add your prepared flour mixture to the wet ingredients. Mix just until everything comes together – be careful not to overdo it, as overmixing can make your cookies tough! Once the dough is combined, cover it tightly and pop it into the refrigerator for at least an hour. This chilling time makes the dough much easier to handle.
Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper. Take your chilled dough (it will be a bit sticky!) and use a small scoop or tablespoon to roll it into uniform balls. Place them about one inch apart on the lined baking sheet. Bake for 8-10 minutes, or just until the cookies are set and appear lightly golden around the edges. Avoid overbaking to keep them soft and tender! Allow the cookies to cool completely on the baking sheet before moving on.
While your cookies are cooling, prepare the icing. In a bowl, combine the sifted powdered sugar. Add the milk one tablespoon at a time, mixing well after each addition, until you achieve a thick, smooth glaze consistency. Stir in the almond extract for that wonderful flavor boost.
Set a cooling rack over a baking sheet (this will catch any excess glaze drips!). Once the cookies are totally cool, hold each one upside down and dip it into the prepared glaze. Flip the cookie right-side up and place it on the cooling rack. Quickly sprinkle with nonpareils before the glaze starts to set, giving your cookies a cheerful and festive finish!