Preheat and prep: Heat your oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or grease well. This helps the delicate almond flour muffins release cleanly.

Mix the cinnamon “sugar” topping: In a small bowl, combine 2 tablespoons granulated sweetener with 1 teaspoon cinnamon. Set aside.

Combine dry ingredients: In a large bowl, whisk 2 cups almond flour, 2 tablespoons coconut flour, 2 teaspoons baking powder, 1/2 teaspoon cream of tartar, 1/2 teaspoon cinnamon, and 1/4 teaspoon salt. Break up any clumps for a smooth batter.

Whisk wet ingredients: In a separate bowl, whisk 3 large eggs, 1/2 cup granulated sweetener, 1/2 cup sour cream, 1/3 cup melted butter, 2 teaspoons vanilla extract, and 1/4 cup unsweetened almond milk until smooth.

Bring it together: Pour the wet mix into the dry mix. Stir gently until just combined. The batter should be thick but scoopable. If it seems too thick, add 1–2 tablespoons more almond milk.

Fill the muffin cups: Spoon a tablespoon of batter into each cup, sprinkle a pinch of the cinnamon topping, then add more batter to fill each cup about 3/4 full. Finish with a final sprinkle of the cinnamon topping for a bakery-style look.

Bake: Bake for 18–22 minutes, or until the tops are set and a toothpick comes out mostly clean with a few moist crumbs. Do not overbake—almond flour dries out faster than wheat flour.

Cool: Let muffins cool in the pan for 5 minutes, then transfer to a rack. They firm up as they cool, giving you that tender, fluffy crumb.

Optional finish: For extra snickerdoodle flair, lightly brush warm muffins with melted butter and dust with a bit more cinnamon sweetener.