If using homemade puree, ensure it’s at room temperature. You can mash a sweet potato after baking it or boiling it, too!
In a small saucepan over medium heat, melt the butter. Continue cooking, swirling the pan occasionally, until the butter turns a deep golden brown and has a nutty aroma. Remove from heat and let cool slightly.
Preheat your oven to 375°Fahrenheit (190°Celsius). Grease a 9x9 inch baking dish or a similar-sized skillet.
In a large bowl, whisk together the sweet potato puree, browned butter, maple syrup, buttermilk, eggs, and vanilla extract until well combined.
Directly add the cornmeal, flour, baking powder, baking soda, kosher salt, cinnamon, and nutmeg to the bowl with the wet ingredients. Stir until just combined. Be careful not to overmix; a few lumps are okay.
Pour the batter into the prepared baking dish or skillet, spreading it evenly.
Bake for 25-30 minutes, or until the top is golden brown and a toothpick inserted into the center comes out clean.
Allow the cornbread to cool in the pan for about 10 minutes before slicing and serving.