Step 1

Place 1 stick unsalted butter for the maple butter on the counter and let sit at room temperature until softened. Meanwhile, make the cornbread.

Step 2

Arrange a rack in the middle of the oven and heat the oven to 375ºF.

Step 3

Place 2 tablespoons of the unsalted butter into a 10-inch cast iron skillet. Place the skillet in the oven and let heat for 8 minutes. Meanwhile, make the batter.

Step 4

Place 1 1/2 cups all-purpose flour, 1 cup stone-ground yellow cornmeal, 1 tablespoon plus 1 teaspoon baking powder, and 2 teaspoons kosher salt in a large bowl and whisk to combine.

Step 5

Place the remaining 8 tablespoons unsalted butter in a medium microwave-safe bowl. Microwave until melted, about 1 minute. (Alternatively, melt the butter on the stovetop and pour into a medium bowl). Add 1 cup plus 3 tablespoons granulated sugar, 1 cup mashed, cooked sweet potatoes, 4 large eggs, 1/2 cup whole milk, 1/2 cup sour cream, and 1 tablespoon maple syrup, and whisk until smooth and combined. Pour into the flour mixture and whisk just until combined. Do not over mix.

Step 6

Carefully remove the hot skillet from the oven. Tilt the skillet in a circular motion so that the melted butter coats the bottom and goes at least halfway up the sides. Pour the batter into the skillet and smooth the top.

Step 7

Return the skillet to the oven and bake until golden-brown, puffy, and a tester inserted into the center comes out clean, 30 to 40 minutes. A few minutes before the cornbread is ready, make the maple butter.

Step 8

Place the softened 1 stick unsalted butter, 3 tablespoons maple syrup, 1/8 teaspoon ground cinnamon, and a pinch of kosher salt in a medium bowl. Beat on low speed with an electric hand mixer until combined. Increase the speed to high and continue mixing until pale and fluffy. Taste and add more maple syrup and kosher salt as needed.

Step 9

Slice the hot or warm cornbread into squares or wedges and serve with the maple butter.