Make the cornbread:
Preheat the oven to 375°F. Spray an 8 by 8-inch baking pan with nonstick cooking spray.
In a medium bowl beat the eggs then whisk in the buttermilk.
In a large bowl whisk together the cornmeal, flour, sugar, baking powder, and salt. Add the buttermilk mixture to the dry ingredients and stir until just combined. Stir in the melted butter and jalapeno peppers.
Pour the batter into the prepared baking dish. Bake until the top is golden brown and the edges have pulled away from the sides of the pan, about 25 minutes. Cool the corn bread in the pan on a wire rack for 10 minutes before turning the bread out onto the rack to cool completely. Dice into medium cubes. If time permits, let the diced corn bread sit out for up to a day before making the stuffing.
Make the stuffing:
Preheat the oven to 350°F. Spray a clean 8 by 8-inch baking pan or similarly shaped 2 quart baking dish with nonstick cooking spray.
Heat a large skillet over medium heat and add the chorizo. Cook, breaking it up, until it begins to brown, about 5 minutes. Add the onion, carrot, celery, and garlic and cook, stirring occasionally, until the vegetables have browned and are softened, about 10 minutes. Add the corn kernels and cilantro and stir to combine. Season to taste with salt and pepper.
In a large bowl toss the diced cornbread with the egg and chicken stock. Add the chorizo mixture and stir until well combined. Pour the mixture into the prepared baking pan. Make ahead: Stuffing can be assembled without the stock and egg 4 hours ahead and kept, loosely covered, at room temperature. Toss in the egg and stock just before baking.
Bake until heated through and golden brown, about 25 minutes.
Make the topping:
Just before the stuffing is done baking, puree 1 diced avocado with the sour cream with a blender, food processor, or immersion blender until very smooth.
Drizzle the avocado sour cream mixture all over the baked stuffing. Top with the remaining diced avocado and serve immediately.