01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together flour, baking powder, baking soda, salt, and poppy seeds in a medium bowl.
03 - Beat softened butter and granulated sugar in a large bowl until light and fluffy, approximately 2 minutes.
04 - Incorporate egg, lemon zest, lemon juice, and vanilla extract, mixing until fully combined.
05 - Gradually blend dry ingredients into wet mixture, mixing just until combined. Avoid overmixing.
06 - Scoop tablespoon-sized dough balls onto prepared baking sheets, spacing 2 inches apart.
07 - Bake for 10-12 minutes until edges are lightly golden. Cool on baking sheet for 5 minutes, then transfer to wire rack.
08 - Beat cream cheese and butter until smooth. Add powdered sugar, lemon juice, vanilla, and salt. Whip until fluffy.
09 - Spread or pipe cheesecake frosting onto completely cooled cookies. Garnish with additional lemon zest or poppy seeds if desired.