Preheat the oven to 350 degrees and line baking sheet with parchment paper
In a small bowl, whisk together flour, baking powder and salt.
In the bowl of a stand mixer cream butter and brown sugar until light and fluffy. Add in egg and vanilla and mix until well incorporated.
Slowly add dry ingredients into the mixer until just combined. Do not overwork the dough or your cookies will come out tough!
Turn the cookie dough out onto a surface dusted with powdered sugar. Use a powdered sugar covered rolling pin to roll out the dough to about ¼ of an inch.
Cut shapes with your favorite cookie cutters and transfer to a parchment lined baking sheet, leaving about 2 inches of room between each shape.
Freeze the cut-outs for 8-10 minutes until the dough is firm.
Bake for 9-11 minutes or until the edges are barely golden. Do not overbake.
Remove the cookies from the oven and let them cool on the baking sheet for at least 5 minutes before transferring them to a wire rack.
Royal Icing
Whisk together powdered sugar, meringue powder, vanilla extract, room temperature water and salt in a small bowl. For thicker icing use less water. To thin it out, add water 1 tsp at a time until desired consistency.
Divide white icing into separate bowls and use gel food coloring to make desired colors.
Decorate cookies and use plenty of festive sprinkles!
Notes
Do not skip chilling the cut-out shapes. Firming up the dough before baking is what will prevent the cookies from spreading across the pan.