Preheat your oven to 350°F (175°C) and line a muffin tin with parchment paper liners or grease it lightly with oil.
In a large mixing bowl, whisk together the 3 eggs, ¾ cup of pure maple syrup, and 1 teaspoon of pure vanilla extract until well combined.
In another bowl, combine 2 cups of almond flour, ¾ cup of tapioca flour, 1 teaspoon of baking powder, and 1 teaspoon of sea salt. Stir until the dry ingredients are evenly mixed.
Gradually add the dry mixture to the wet ingredients, stirring gently with a spatula until just combined. Be careful not to overmix.
Gently fold in the 1 ½ cups of fresh blueberries and the zest of 1 lemon, if using. This adds a refreshing hint of citrus that elevates the flavor.
Evenly distribute the muffin batter into the prepared muffin tin, filling each cup about ¾ full.
Bake in the preheated oven for 20-25 minutes or until a toothpick inserted in the center comes out clean. The tops should be golden brown and slightly domed.
Once baked, remove the muffins from the oven and allow them to cool in the tin for about 5 minutes before transferring them to a wire rack to cool completely. Enjoy them warm or at room temperature!