Preheat the oven to 425 degrees F (220 degrees C).
Heat olive oil in a skillet over medium-high heat. Add onion and red bell pepper; saute until softened, 5 to 7 minutes. Add ground beef, garlic, chili powder, cayenne pepper, salt, and black pepper. Cook and stir until beef is browned and crumbly, 5 to 7 minutes.
Mix corn into the beef mixture and toss to defrost, about 3 minutes. Drain and discard fat. Add about 1/4 of the shredded Mexican cheese blend and mix well. Pour meat sauce into a 9x13-inch casserole dish. Cover meat with a thin layer of salsa.
Combine cornmeal, salt, and baking soda in a large bowl. Add milk and eggs; stir until well blended. Pour cornmeal mixture on top of salsa layer and top with remaining shredded Mexican cheese blend.
Bake in the preheated oven until browned on top, about 30 minutes.