In a medium bowl, whisk together 2 cups of all-purpose flour, 2 tablespoons of poppy seeds, 1 teaspoon of baking soda, 1 teaspoon of baking powder, and ½ teaspoon of salt.

In a large mixing bowl, rub the zest of 1 lemon into 1 cup of granulated sugar until fragrant. Then, add ½ cup of softened unsalted butter and cream together using an electric mixer on medium speed for about 3 minutes.

Add 1 large egg, 2 tablespoons of freshly squeezed lemon juice, and 1 teaspoon of vanilla extract to the creamed mixture, mixing on low speed until fully combined.

Gradually add the dry mixture to the wet mixture, mixing on low speed until just combined.

Cover the dough with plastic wrap and refrigerate for at least 2 hours.

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

Using a cookie scoop or tablespoon, portion out the chilled dough into 2-tablespoon mounds and place them about 2 inches apart on the prepared baking sheet.

Bake the cookies for 8 to 10 minutes, or until the edges are set.

Allow the cookies to cool on the pan for about 5 minutes before transferring them to a wire rack.

In a small bowl, mix 1 cup of icing sugar with 2 tablespoons of lemon juice until smooth, then drizzle over the cooled cookies.