In a large bowl, add the room temperature butter and almond extract. With an electric mixer, beat on high for 2-3 minutes until light, airy, and smooth.
Slowly add the powdered sugar in thirds and beat on medium speed with your mixer in between each addition. Once all of the sugar has been mixed, it will be a dry and crumbly mixture.
Add the milk 1-2 tablespoons at a time, beating on high each time. Once the mixture starts to smooth out like frosting, turn up the mixer to high and beat for 2-3 minutes to whip up the icing. It will be done when it's almost white, smooth, and easily spreadable.
Frost your cooled cookies with an icing knife or a piping bag. The frosting will slightly crust over as it dries.
Notes
*Decorating Tip: Place the cookies on parchment paper on a cookie sheet to decorate. This gives them a nice flat surface to dry and can be easily moved out of the way!