Preheat the oven to 350°F (175°C).

In a mixing bowl, cream together the softened butter and granulated sugar until light and fluffy.

Beat in the egg and vanilla extract until well combined.

In a separate bowl, whisk together the flour, baking powder, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Drop spoonfuls of dough onto a baking sheet lined with parchment paper.

Bake for 10-12 minutes or until the edges are lightly golden.

Remove from the oven and let cool completely.

In a small bowl, whisk together the powdered sugar, orange juice, lemon juice, orange zest, and lemon zest until smooth.

Once the cookies are cooled, drizzle the citrus glaze over the top of each cookie.

Allow the glaze to set before serving.