Beat the softened butter and 1/2 cup powdered sugar together until light and fluffy, about 1-2 minutes.
Mix in the lemon juice, lemon zest, and vanilla extract until combined.
Add the flour and salt and mix on low speed just until a soft dough forms.
Preheat the oven to 350F. Scoop the dough into 1-tablespoon portions and roll into smooth balls.
Place the balls 2 inches apart on lined baking sheets and bake for 12-14 minutes, until set but still pale on top.
Cool on the pan for 5 minutes, then roll each cookie in powdered sugar while still warm.
Once fully cooled, roll the cookies in powdered sugar again for a thick, snowy coating.