In a bowl, whisk flour, baking powder and salt. Set aside.
In a separate bowl, cream the butter and cream cheese. Add in the sugar and beat until light and fluffy. Add egg, vanilla extract and beat until combined.
Add the flour mixture and stir until combined. Use a spatula to scrape the bottom. Cover and refrigerate for at least 1 hour.
Preheat oven to 375F (190C).
Roll the dough into 1-2 inch balls. Place on a baking tray lined with parchment paper and flatten slightly the cookies.
Bake for 9-11 minutes, or until the edges are set.
Allow to cool before serving. Dust with icing sugar.
Notes:
Keep the cookies in a closed container in the fridge un to 5 days.