Prep your tools: Line a baking sheet with parchment paper. Set oven to 350°F (175°C), but you’ll chill the dough first.

Make the cinnamon “sugar” mix: In a small bowl, combine 2 tablespoons granular keto sweetener with 1.5 teaspoons ground cinnamon. Set aside for rolling.

Cream the butter and sweeteners: In a medium bowl, beat 1/2 cup softened butter with 1/3 cup granular sweetener and 2 tablespoons brown keto sweetener until fluffy, about 1–2 minutes.

Add the egg and vanilla: Beat in 1 large egg and 2 teaspoons vanilla extract until smooth.

Whisk dry ingredients: In another bowl, whisk 1.5 cups almond flour, 2 tablespoons coconut flour, 1 teaspoon cream of tartar, 1/2 teaspoon baking soda, and 1/4 teaspoon fine sea salt.

Combine: Add dry ingredients to the wet mixture. Mix until a soft dough forms. It should be slightly sticky but scoopable.

Chill: Cover and refrigerate the dough for 20–30 minutes to firm up. This helps the cookies keep their shape.

Portion: Scoop dough into 1–1.5 tablespoon portions. Roll each into a ball, then roll in the cinnamon sweetener mix to coat.

Arrange: Place on the lined baking sheet, spacing about 2 inches apart. Gently flatten each ball with your fingers or the bottom of a glass to about 1/2 inch thick.

Bake: Bake for 9–11 minutes until the edges are set and just starting to turn golden. The centers will look slightly soft.

Cool: Let cookies cool on the sheet for 10 minutes, then transfer to a rack to cool completely. They firm up as they cool.