Preheat the oven to 375 degrees F. Grease a (12 cup) muffin pan or line with muffin liners.
In a large bowl, whisk together the egg, melted butter, and honey. Add the flax meal and mix well. Whisk in the milk.
Stir in the remaining dry ingredients, adding the millet last.
Spoon into the prepared muffin pan. (I like to use an ice cream scoop with a release for an even and mess-free transfer. The batter will divide almost perfectly into 12 scoops.)
Bake for 15 minutes, give or take a few minutes depending on the oven, or until the muffins are just cooked through the center and pass the toothpick test. (In my oven, these muffins take exactly 14 minutes.)
Allow to cool in the pan for 5 minutes before removing to a cooling rack.
