How to make it

1. Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. In a medium bowl, whisk together the flour, baking soda, and salt.
3. In a large bowl, cream together the butter, granulated sugar, and brown sugar until light and fluffy.
4. Beat in the egg, vanilla extract, lemon zest, and lemon juice until well combined.
5. Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
6. Scoop tablespoon-sized balls of dough (about 25 g each) onto the prepared baking sheet, spacing them 2 inches apart.
7. Bake for 10-12 minutes or until the edges are lightly golden. Let cool on the baking sheet for 5 minutes before transferring to a cooling rack.
8. While the cookies cool, prepare the lemon cream filling. Beat the butter until smooth, then gradually add the powdered sugar, lemon juice, and lemon zest, beating until creamy and smooth.
9. To assemble, spread a generous amount of lemon cream filling on the flat side of one cookie and sandwich with another cookie, pressing gently to spread the filling to the edges.