Preheat the oven to 350 degrees F (175 degrees C). Lightly grease a medium baking dish with cooking spray.

Cook sausage in a large, deep skillet over medium-high heat until evenly browned and crumbly, 5 to 7 minutes. Drain.

Mix cornbread mix, corn, and water together in a medium bowl. Spread 1/2 of the cornbread mixture over the bottom of the prepared baking dish. Layer sausage over top, then onion, jalapeño, and cheese. Top with remaining cornbread mixture, using only as much as fits in the baking dish.

Bake in the preheated oven until a toothpick inserted in the center comes out clean, about 35 minutes. Let cool for about 10 minutes before serving.