Preheat the oven to 400°F. Boil the sweet potatoes until very tender, then mash until smooth and soft. Measure out 1 ½ cups of mashed sweet potatoes and let cool slightly.
In a small saucepan, melt the butter, and slowly whisk in the honey. Remove from heat. You can also use a microwave.
In a large mixing bowl, use a hand mixer to blend the mashed sweet potato, milk, oil, eggs, vanilla, and optional food coloring until smooth and creamy.
In another large bowl, whisk together the cornmeal, flour, sugar, baking powder, and salt.
Add the dry mixture to the wet ingredients, folding until just combined. Don’t overmix.
Pour the batter into a greased 9x13-inch pan or cast iron skillet. Bake for 25 to 30 minutes, or until a toothpick comes out clean. After 20 minutes in the oven, brush a layer of honey butter, and continue to cook. Your cornbread is ready if you insert a wooden toothpick in the center and it comes out clean.
Let cool slightly, then slice and serve warm with more honey butter.