Prep the pan. Preheat the oven to 350°F. Grease or butter an 8x8-inch baking pan, then line it with a parchment paper sling.
Mix the dry ingredients. In a large bowl, whisk together the flour, cornmeal, baking powder, salt, and baking soda.
Mix the wet ingredients. In a separate bowl, whisk together the pumpkin, yogurt, melted butter, brown sugar, and eggs.
Combine the batter. Add the wet ingredients to the dry ingredients. Stir just until combined and no dry streaks remain. A few small lumps are fine, so don't overmix.
Fill the pan. Spread the batter evenly in the prepared pan. Sprinkle the pepitas over the top.
Bake. Bake until the top is set, the edges are lightly golden, and a toothpick inserted in the center comes out clean or with a few moist crumbs, about 30 to 40 minutes.
Make the maple butter. When the cornbread has about 5 minutes left in the oven, whisk together the warm melted butter, maple syrup, and cayenne in a small saucepan or microwave-safe bowl.
Glaze. Brush the maple butter over the top of the cornbread as soon as it comes out of the oven.
Rest and serve. Let the cornbread stand for at least 10 to 15 minutes before slicing. Serve warm or at room temperature.