In a medium bowl combine the flour, baking powder, salt, cinnamon, and nutmeg. Mix well and set aside.
In a large bowl cream together the butter and sugar. Add in the egg and vanilla and mix well.
Add the flour mixture to the butter mixture and mix until a dough has formed.
Wrap the dough in plastic wrap and refrigerate for at least 2 hours.
When ready to make the cookies preheat the oven to 350 degrees.
Remove the cookie dough from the refrigerator.
Dust a surface with flour and roll out the dough to 1/2 inch thickness.
Use a cookie cutter and cut out shapes. I used an ornament cutter.
Bake for 9-10 minutes or just until cookies are set.
Remove cookies to a wire rack and cool completely.
To make the royal icing place the powdered sugar and meringue powder in a small bowl. Add in the water a little at a time, mixing after each addition, until a thick icing forms.
Put the icing in a zip top baggie, cut off the end, and pipe onto the cookies to decorate. Sprinkle with the sprinkles.