Preheat oven to 350°F. Line baking sheets with parchment paper.

In the bowl of a stand mixer or using a hand-held mixer, mix the butter and cornstarch until well combined and lighter in color.

With the mixer off, add confectioners' sugar.

With the mixer on low, add the lemon extract and mix until ingredients are fully incorporated.

Turn mixer off and add flour. With the mixer on low to medium-low, mix until the dough comes together (pulls away from sides of the bowl).

Using a 1 tablespoon cookie scoop, remove about a tablespoon of dough. Place onto the lined cookie sheet at least 2 inches apart.

Once the cookie sheet is full, gently roll each between your hands until it is a smooth ball.

Bake for 8 to 10 minutes.

Right out of the oven take a glass with a flat bottom and gently press it into the cookie.

Allow cookies to cool for about 5 minutes and then move to a cooling rack. Make sure cookies are completely cool before adding glaze.

In a medium bowl add 1 cup of confectioners' sugar, 3.5 teaspoons of milk, and 1 teaspoon of lemon extract. Stir until smooth.

Place in a piping bag and seal with a rubber band, or spoon onto the cooled cookies.