In a wide shallow bowl or container, whisk together milk, melted vegan butter or coconut oil, flour, sugar, vanilla, cinnamon, nutmeg and kosher salt.
Preheat a griddle over medium high heat and melt another 1 tablespoon vegan butter or coconut oil. Soak each side of 4 to 5 slices of bread in the egg mixture until it becomes saturated, about 15 seconds per side. Place the bread on the hot skillet and cook 3 to 4 minutes per side, until browned.
Serve immediately with maple syrup and a dusting of powdered sugar or dust with cinnamon sugar (per the instructions in Cinnamon French Toast).