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

In a large bowl, cream the softened butter, powdered sugar, and granulated sugar with a mixer until light and fluffy, 2–3 minutes.

Beat in lemon zest, lemon juice, and vanilla extract until well combined.

In a separate bowl, whisk together flour, baking powder, and salt. Gradually add the dry ingredients to the butter mixture, mixing just until a soft dough forms.

Roll dough into 1-inch balls and place 2 inches apart on the prepared baking sheet.

Bake for 10–12 minutes, or until the edges are set and the tops look matte but not browned. Do not overbake.

Let cookies cool on the sheet for 2–3 minutes, then roll gently in powdered sugar while still warm to create the first light coating.

Transfer to a wire rack to cool completely. Once cool, roll again in fresh powdered sugar for a thick, snowy finish.