Ingredients
Method
- Heat oven to 375°F; parchment-line two sheets. Beat butter and dough sugar 2 minutes; add egg, yolk, and vanilla.
- Whisk flour, cream of tartar, baking soda, and salt; mix into butter just until flour disappears.
- Mix coating sugar and cinnamon. Form 24 dough balls; roll in cinnamon sugar.
- Space 2 inches apart; bake one sheet at a time 9 to 10 minutes until rims set and centers puffed but soft.
- Stand on hot sheets 5 minutes; transfer to racks. Centers settle into wrinkles as they cool.