Prep the pan: Heat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or grease well.
Whisk dry ingredients: In a large bowl, whisk 2 cups almond flour, 2 tablespoons coconut flour, 1/2 cup keto sweetener, 2 teaspoons baking powder, 1/2 teaspoon kosher salt, and 1/2 teaspoon cinnamon.
Mix wet ingredients: In a separate bowl, whisk 3 large eggs, 1/3 cup melted butter (or 1/3 cup avocado oil), 1/2 cup sour cream, 1/3 cup unsweetened almond milk, 3 tablespoons sugar-free maple syrup, 1 teaspoon vanilla extract, and 1/2 teaspoon maple extract.
Combine: Pour wet ingredients into the dry.
Stir with a spatula until just combined. The batter should be thick but scoopable. If it’s too thick, add 1–2 teaspoons almond milk.
Optional add-ins: Fold in 1/3 cup chopped pecans or 1/4 cup sugar-free chocolate chips.
Portion: Divide the batter evenly among the 12 cups.
For a bakery look, sprinkle tops with a pinch of keto sweetener and cinnamon.
Bake: Bake 16–20 minutes, until the tops are set and a toothpick comes out mostly clean with a few moist crumbs.
Cool: Let muffins cool in the pan 5 minutes, then transfer to a rack. Cool fully for best texture.
Optional glaze: For extra maple, whisk 2 tablespoons powdered keto sweetener with 1–2 teaspoons sugar-free maple syrup and a splash of almond milk. Drizzle over cooled muffins.