Preheat the oven to 325F.

Microwave the butter for 30-45 seconds to melt it.

Add all dry ingredients into a bowl and combine well.

Add in the egg and melted butter and mix. The dough should be thick but not sticky.

Roll the cookies into 2-3 tbsp-sized balls and place them on a cookie sheet.

Cook at 325F for 12-15 minutes. Cookies will only brown around the bottom edges.

Let cool completely.

Combine all royal icing ingredients in a bowl.

Once the cookies are cooled, use a large spoon to start the icing in the center of the cookie. Leave room around the edges for a classic look!

Gently shake the cookie to even out the icing. Let the iced cookies sit for a minimum of five minutes. A shell should form from the icing.

Using a toothpick or tube of black icing, draw lines on your cookie as the Christmas light string.

Add colorful M&Ms around the black line to add your lights. Enjoy!