Whisk the all-purpose flour, cream of tartar, baking soda, fine salt, and ground vanilla bean in a bowl.

Beat the unsalted butter and 3/4 cup granulated sugar with a hand mixer on medium speed for 2 minutes, until lighter and fluffy. Beat in the egg until combined.

Add the dry ingredients and mix on low just until no dry flour remains. Cover and refrigerate for 30 minutes.

During the final 10 minutes of chilling, heat the oven to 375°F. Line two baking sheets with parchment. Mix the remaining 2 tablespoons granulated sugar with the ground cinnamon in a shallow bowl.

Divide the dough into 20 equal portions, roughly 1 1/2 tablespoons each. Roll into balls, coat in cinnamon sugar, and arrange 2 inches apart on the sheets. Flatten very lightly with your palm.

Bake one sheet at a time on the center rack for 9 to 11 minutes, until the edges are set and the tops are puffed with fine cracks and no wet sheen. The centers should still feel soft. Allow approximately 20 minutes for both batches.

Let each batch sit on its baking sheet for 10 minutes, then transfer to a wire rack for at least 10 more minutes before serving. Cool completely before storing.