The star cookie recipe is from the book what Einstein told his cook. I made a few changes in my cookies. I made them gluten free and sugar free, and surprisingly they tasted really good!

• 2 1/4 cup all purpose flour (or gluten free flour) plus flour for dusting
• 1 teaspoon cream of tartar
• 1/2 teaspoon baking soda
• 1/4 teaspoon salt
• 1/2 cup (1 stick) unsalted butter
• 1 cup sugar(or stevia/monk fruit)
• 2 large eggs, lightly beaten
• 3/2 teaspoon vanilla
• 1 egg yolk mixed with 1 teaspoon water
• Sugar for topping!

• In a medium bowl, stir together, cream of tartar, baking soda, and salt. In a large mixing bowl, cream the butter And sugar with an electric mixer. Beat in the eggs and vanilla until combined. Add the dry ingredients and, using a wooden spoon, mix until a dough is formed.
  
• Divide and roll out the dough, refrigerate dough (optional, I didn’t refrigerate).
• preheat the oven to 350 Fahrenheit. If you choose to refrigerate your dough take it out, and you may have to wait for it to chill, so it’s easier to roll out. Dust with flour on top and bottom. Use star shaped cutter( or any shape). Line your baking tray with parchment paper, and brush with your egg yolk and water mixture, then lightly sprinkle with sugar. Bake for 10 to 12 minutes or until lightly brown, the slightly underbaked cookies were the best in my opinion, they will cook throughout once they sit on a cooling rack, it makes them soft instead of crunchy. Let the cookies cool for about 2 minutes, or burn your mouth like I did, because I’m impatient. The cookies can stay good for a few weeks if you keep them in a airtight container, or put them in the freezer until your ready to eat them. Happy baking I hope you enjoy!