Preheat your oven to 400°F (200°C). Grease a 9x5-inch loaf pan or line it with parchment paper for easy removal.
In a large mixing bowl, combine the cornmeal, all-purpose flour, baking powder, salt, and sugar. Whisk together until well blended.
In a separate bowl, whisk together the buttermilk, melted butter, eggs, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients and stir gently until just combined. Be careful not to overmix; a few lumps are okay.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake in the preheated oven 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 transferring it to a wire rack to cool completely.