Preheat the oven to 350 degrees and grease a 12-cup muffin pan. Line with paper liners if desired.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
In a large bowl, mix the eggs, maple syrup, coconut milk, melted coconut oil, and vanilla. Add the dry ingredients to the wet ingredient mixture and mix to combine.
If using frozen berries, rinse them under cold water until the water runs clear to avoid discoloration in the muffin batter (optional). Fold the berries into the batter. Transfer the batter to the muffin pan.
Bake for 20 to 25 minutes, until a toothpick inserted in the center comes out clean. (If using frozen berries, you’ll need the slightly longer cook time). Cool on a cooling rack before serving.