Whisk together the flour, baking powder, and salt in a bowl.
Cream the softened butter and sugar until light and fluffy.
Add the egg, vanilla extract, and lemon zest, then mix well.
Gradually add the dry ingredients to the wet mixture.
Add milk if needed to bring the dough together.
Divide and wrap the dough, then chill for 30 minutes.
Preheat the oven to 350°F (175°C).
Roll the dough to 1/4-inch thickness and cut into spring shapes.
Arrange on a parchment-lined baking sheet.
Bake for 8 to 10 minutes until the edges are lightly set.
Cool completely.
Decorate with icing and sprinkles.
