Preheat oven: Heat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or grease with coconut oil.
Mix dry ingredients: In a large bowl, whisk together almond flour, coconut flour, baking soda, and salt until well combined.
Prepare wet ingredients: In another bowl, whisk together eggs, honey, melted coconut oil, almond milk, vanilla extract, and lemon zest until smooth.
Combine wet and dry: Pour wet ingredients into dry ingredients and stir until just combined. Don't overmix - the batter should be slightly lumpy.
Fold in blueberries: Gently fold fresh blueberries into the batter, being careful not to burst them.
Fill muffin cups: Divide batter evenly among muffin cups, filling each about 3/4 full. Sprinkle sliced almonds on top.
Bake: Bake for 20-25 minutes, or until tops are golden brown and a toothpick inserted in center comes out clean or with just a few moist crumbs.
Cool: Let muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.