Reduce the Apple Cider: In a small saucepan over medium heat, simmer 1.5 cups of fresh unfiltered apple cider for 12 to 15 minutes until it reduces down to exactly 1/3 cup of rich amber syrup. Set aside to cool completely.

Whisk Dry Ingredients: In a medium bowl, whisk together all-purpose flour, cream of tartar, baking soda, fine sea salt, ground cinnamon, nutmeg, and allspice until evenly aerated.

Cream Butter & Sugars: In a stand mixer fitted with paddle attachment, beat softened butter, granulated sugar, and brown sugar on medium speed for 2 to 3 minutes until light and fluffy.

Add Wet Aromatics: Beat in the egg, egg yolk, cooled apple cider reduction, and pure vanilla extract until smooth and creamy.

Form Dough & Chill: Gradually add the dry flour mixture on low speed just until combined. Cover and chill the dough in the refrigerator for 30 minutes to firm up for rolling.

Roll in Cinnamon Sugar: Preheat oven to 350°F (175°C) and line baking sheets with parchment paper. In a small bowl, stir together 1/3 cup sugar and 1.5 tbsp cinnamon. Scoop 1.5-tablespoon portions of chilled dough, roll into balls, then roll generously in cinnamon sugar until heavily coated.

Bake to Pillowy Perfection: Place dough balls 2 inches apart on baking sheets. Bake for 9 to 11 minutes just until the edges are set and crinkled, but the centers remain soft and puffed. Do not overbake!

Cool & Enjoy: Let cookies rest on the warm baking sheet for 5 minutes to settle into chewy crinkly perfection, then transfer to a wire rack to cool. Serve warm!