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

Add the egg and vanilla extract, mixing 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 a dough forms.

Preheat the oven to 350?F (175?C).

Roll out the dough on a floured surface to about 1/4 inch thick.

Use a sombrero-shaped cookie cutter to cut out cookies and place them on a baking sheet.

Bake in the preheated oven for 12-15 minutes or until the edges are lightly golden.

Allow cookies to cool completely before decorating.

Using royal icing, decorate the cookies in festive colors to resemble sombreros.

Add sprinkles if desired for extra decoration.