Step 1

In a medium mixing bowl, whisk together the all-purpose flour, baking powder, and salt. Set to the side.

Step 2

Using your hand mixer or stand mixer fitted with the paddle attachment, beat together the unsalted butter, granulated sugar, light brown sugar, lemon zest, lemon juice, and vanilla extract on medium-high speed until well blended.

Step 3

Reduce the mixer speed to low, gradually adding in the whisked dry ingredients, mixing until just combined.

Step 4

Adjust oven rack to the 2nd level position (just above center), preheat oven to 300ºF, and line a cookie sheet with parchment paper or silicone baking mat.

Step 5

Using a spoon or a 1 tablespoon-size cookie scoop, roll the cookie dough into balls. Place roughly 1 1/2 inches apart on the prepared cookie sheets. You can also use a 1 1/2 tablespoon-size cookie scoop which will yield slightly fewer cookies.

Step 6

With the bottom of a glass, gently press down on the tops of each cookie to flatten slightly. I recommend dipping the bottom of the glass in some flour so the cookies won't stick to the glass.

Step 7

Bake for 15-20 minutes at 300ºF or until the edges are a light golden brown. For reference, mine baked for 18 minutes. If baking these cookies on smaller cookie sheets, one at a time, I recommend keeping the cookie dough stored in the refrigerator until you're ready to bake the next batch.

Step 8

The cookies will still be very soft—let them cool on the cookie sheet for about 5-10 minutes first before transferring them to a wire cooling rack to finish cooling.

Step 9

In a small mixing bowl, whisk together the powdered sugar, lemon juice, and milk until well combined. Using a spoon, drizzle some lemon glaze over each cookie. You can also dip the tops of each cookie into the glaze. Let any extra glaze drip off, then enjoy!

Step 10

Store cookies at room temperature in a sealed container for up to 5 days. Lemon shortbread cookies can also be stored in the freezer for up to 4 months. Place them in a well sealed container separating cookies with a layer of wax paper.