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

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

Add the egg and vanilla extract to the mixture and beat until well combined.

In a separate bowl, whisk together flour, baking powder, and salt until well mixed.

Gradually add the dry ingredients to the wet mixture, stirring until a soft dough forms.

Scoop approximately 1-inch balls of dough and roll each ball in pastel sanding sugar.

Arrange the sugar-coated dough balls on the lined baking sheet, leaving space between each.

Bake for 8-10 minutes, ensuring the edges are set while the centers remain slightly soft.

Remove the cookies from the oven and press a chocolate kiss into the center of each cookie while warm.

Cool the cookies on the baking sheet for 3-5 minutes before transferring to a wire rack.