Preheat the oven to 375 degrees F, and line an 8x8 baking pan with parchment paper. Grease the sides without parchment paper.
In a large mixing bowl, whisk together cornmeal, baking powder, baking soda, cinnamon, and sea salt.
In a separate bowl, whisk together sweet potato puree, yogurt, honey, butter, and eggs.
Add wet ingredients to dry ingredients, and mix until just combined.
OPTIONAL: If adding zucchini, squeeze out as much liquid as possible. Fold into the batter.
Pour the batter into the prepared baking dish and flatten the top with a spatula.
Bake for 25-30 minutes until golden on top and a toothpick inserted in the center comes out clean.
For a shiny top to the cornbread, spread some butter when it's fresh out of the oven.
Cool for 10 minutes, then remove from the pan and slice into 16 squares. You can serve with butter and more honey.