Heat the oven to 375 degrees. Coat 6 (6 to 8 ounce) ramekins with non-stick cooking spray.
Cook the ground beef in a large skillet over medium-high heat for 5 to 7 minutes or until thoroughly cooked and no longer pink in the center, stirring frequently. Stir in the tomatoes, corn and Mexican seasoning. Simmer over low heat for 5 minutes. Stir in the cilantro.
Meanwhile, whisk the corn muffin mix, 1/2 cup sour cream and egg in a medium bowl until combined.
Spoon half of the corn muffin mixture into the ramekins. Top with the ground beef mixture and the remaining corn muffin mixture. Sprinkle each with the cheese.
Bake for 20 minutes or until the corn muffin mixture is lightly browned and a toothpick inserted in the center comes out clean. Serve dolloped with the remaining sour cream.