Preheat the oven to 180C/350F. Line a 12-count muffin pan with muffin liners and set aside.
In a mixing bowl, combine your coconut flour with baking powder and mix well. Set aside. In a separate bowl, whisk together your eggs, softened butter, milk, honey, and vanilla extract until combined.
Gently fold through your dry ingredients into the wet until combined. Add the blueberries, if using them. Distribute the batter amongst the muffin liners.
Bake the muffins for 15 minutes, before removing from the oven and letting cool in the pan for 10 minutes, before transferring to a wire rack to cool completely.
TO STORE: If you intend to eat the muffins within 2 days, they can be stored at room temperature, in a sealed container. If you'd like it to keep longer, store them in the refrigerator for up to 1 week. TO FREEZE: Place the muffins in a ziplock bag and store them in the freezer for up to 6 months.