Preheat the Oven: Set your oven to 375°F and prepare cookie sheets by lining them with parchment paper or silicone baking mats.

Mix the Dry Ingredients: In a medium-sized bowl, whisk together 2 cups of all-purpose flour, 1 tablespoon of baking powder, and ½ teaspoon of salt. Set the mixture aside.

Cream Butter and Sugar: In a large mixing bowl, beat ¼ cup of room-temperature unsalted butter with ½ cup of granulated sugar using an electric mixer for about 1 minute, or until the mixture is pale and fluffy.

Add Wet Ingredients: Add in 1 large egg and ¼ teaspoon of vanilla extract, beating until smooth and fully incorporated. Then mix in 2 tablespoons of fresh lemon juice and 1 tablespoon of lemon zest.

Combine Wet and Dry: Gradually incorporate the dry ingredients into the wet mixture, alternating with ⅓ cup of milk. Start by adding half the flour mixture, stir, then add the milk, and finish by mixing in the remaining dry ingredients. The resulting dough will be thick and a bit sticky.

Scoop the Dough: Using a small cookie scoop or tablespoon, portion out the dough and place rounded scoops onto the prepared cookie sheets, leaving space between each for spreading.

Bake the Cookies: Place the trays in the preheated oven and bake for 11 to 13 minutes, or until the bottoms of the cookies are lightly golden. Remove from the oven and let the cookies cool completely on wire racks.

Make the Glaze: In a separate bowl, beat together 1½ cups powdered sugar, 2 tablespoons of room-temperature unsalted butter, 1½ tablespoons milk, 1 tablespoon lemon juice, and ½ tablespoon lemon zest until the glaze is smooth and slightly pourable.

Glaze the Cookies: Set the cooling racks with cookies over foil or a baking sheet. Spoon or drizzle about a teaspoon of glaze over each cooled cookie. Allow the glaze to set for 15 to 20 minutes.

Serve and Store: Enjoy the cookies right away or store them in an airtight container to keep them fresh until you're ready to serve.