01 -
Preheat oven to 325°F.
02 -
In a medium mixing bowl, combine butter, 3/4 cup sugar, and brown sugar until light and fluffy.
03 -
Add egg, egg yolk, and vanilla extract and mix until combined.
04 -
Add baking soda, cream of tartar, salt, and 1 teaspoon cinnamon. Mix until incorporated.
05 -
Gradually mix in flour just until combined, avoiding overmixing.
06 -
In a small bowl, combine 3 teaspoons ground cinnamon and 1/2 cup sugar to create the coating mixture.
07 -
Scoop approximately 2 tablespoons of dough and roll into a ball. Coat each ball in the prepared cinnamon sugar mixture.
08 -
Place the dough balls on a greased baking sheet about 2 inches apart. Bake for 10 minutes, or until the edges are slightly golden.