Combine the flour, salt and baking powder. If your flour mix doesn’t have xanthan gum, add one teaspoon to this mixture.
Place the butter and cream cheese in a large bowl and beat together for 2 minutes on high speed using a hand-held mixer. The mixture should be creamy and smooth. Bring in the sugar and mix on medium speed until fluffy. Add the vanilla extract and egg and mix again until well incorporated.
Add the dry ingredients to the wet and mix on low speed until combined. You will get a thick cookie dough. Cover the bowl with a plastic wrap and take it to the fridge for at least one hour.
Take the dough out of the fridge. In case you left it to chill more than 4 hours, allow it to sit at room temperature for 20 minutes so you are able to scoop it.
Preheat the oven to 375F. Line two baking trays with parchment paper. Set aside.
Take tablespoons of dough and roll them into balls. Place them on the already prepared trays. Leave a space of about 1 ½ inches between the dough balls. Flatten them a bit with the back of a spoon or a measuring cup.
Bake the cookies for 15-17 minutes until they get a light brown color around the edges. You may rotate the tray after 10 minutes so the cookies will be baked evenly. You will notice that they look soft in the middle when removing from the oven but do not overbake because they lose their soft and tender texture.
Let them chill for 5 minutes before taking them to a wire rack. The cookies need to be completely cool when you decorate them.