Preheat and prep: Set your oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly grease it.

Mix dry ingredients: In a large bowl, whisk together 2 cups almond flour, 2 tablespoons coconut flour, 2 teaspoons baking powder, and 1/4 teaspoon salt until no lumps remain.

Whisk wet ingredients: In a separate bowl, whisk 3 large eggs, 1/2 cup granulated erythritol, 1/2 cup sour cream, 1/3 cup melted butter (slightly cooled), and 1 1/2 teaspoons vanilla extract. Add 1 teaspoon lemon zest if using.

Combine: Pour the wet mixture into the dry and stir with a spatula until just combined. The batter should be thick but scoopable. If it seems too stiff, add 1–2 tablespoons of unsweetened almond milk.

Fold in raspberries: Gently fold in 1 cup raspberries. If using frozen, add them straight from the freezer and fold minimally to avoid streaking.

Fill the tin: Divide the batter evenly among the muffin cups, filling each about 3/4 full. For extra lift, mound the batter slightly in the center.

Bake: Place on the middle rack and bake for 18–22 minutes, or until the tops are set and a toothpick comes out clean or with a few moist crumbs.

Cool: Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack. Almond flour muffins firm up as they cool, so be patient before digging in.