For the cookies:
-4 cups all purpose flour
-1/2 tsp cream of tartar
-1 tsp salt
-1 tsp baking powder
-1 1/2 cups unsalted butter, room temperature
-2 cups sugar
-2 egg yolks
-5 tsp vanilla extract
For the icing:
-2 tbsp meringue powder
-4 cups powdered sugar, sifted
-6 tbsp warm water plus any extra for diluting
1. In a large bowl, sift together the flour, cream of tartar, salt and baking powder. Set aside.
2. Beat the butter until light and fluffy. Then add in the sugar and beat until well combined.
3. Add in the eggs and egg yolks one at a time, making sure to mix well after each addition. Then stir in the vanilla.
4. Slowly add the dry mixture to the wet, mixing until just combined.
5. Cover the dough and refrigerate for at least one hour.
6. Preheat oven to 350 degrees Fahrenheit.
7. Turn out the dough onto a floured surface, roll it out and cut out desired shapes. Place dough on an ungreased cookie sheet and bake for 6 to 8 minutes. Allow to cool completely on a rack before decorating.
Tip: If you have warm hands like I do you're going to want to work with a bit of the dough at a time and keep the rest in the fridge. If the dough becomes too soft to work with, place it in the freezer for a few minutes.
8. Place all of the icing ingredients into your mixing bowl and beat on low until smooth. Color as desired and decorate cookies.
Tip: To color the royal icing, I strongly recommend using gel or paste food coloring as liquid would dilute the icing too much. But if you do need to thin out the icing, add a half teaspoon of water at a time until it reaches your desired consistency. Also, be sure to keep your icing covered when you're not using it or it will start to harden and become grainy.
9. Consume and enjoy!