Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly grease it.
In a large mixing bowl, combine almond flour, baking soda, and salt.
In another bowl, whisk eggs, maple syrup (or honey), melted coconut oil, vanilla extract, and lemon zest.
Gradually add wet mixture into the dry ingredients and stir until just combined.
Gently fold in the blueberries.
Divide the batter evenly among the muffin cups. Top with sliced almonds if desired.
Bake for 20–25 minutes or until a toothpick inserted in the center comes out clean.
Let cool for 5 minutes in the pan, then transfer to a wire rack.