Preheat the Oven:
Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper.

Cream Butter and Sugar:
In a large mixing bowl, beat the butter and sugar together until light and fluffy.

Add Wet Ingredients:
Mix in the egg, vanilla extract, lemon juice, and lemon zest until fully combined.

Mix Dry Ingredients:
In a separate bowl, sift together the flour, baking powder, and salt.

Combine Wet and Dry:
Gradually add the dry ingredients to the wet mixture, alternating with the milk. Mix until just combined—do not overmix.

Scoop the Dough:
Scoop the dough into roughly ¼ cup portions and place them evenly spaced on the prepared baking sheet.

Bake:
Bake for 9–11 minutes, or until the edges are just starting to turn golden.

Cool and Glaze:
While cookies cool, whisk together the glaze ingredients in a small bowl until smooth. Once the cookies have cooled, spoon the glaze over each cookie.