In a large bowl, combine cereal and milk; let stand for 10 minutes. Stir in sour cream and egg. Stir in bread mix just until moistened.
Fill greased or paper-lined muffin cups about three-fourths full. Cut cream cheese into 12 cubes; gently press one cube into the center of each muffin cup just until covered with batter (cups will be full).
Bake at 400° for 18-20 minutes or until a toothpick inserted in the center comes out clean. Cool for 5 minutes before removing from pan to a wire rack. Serve warm. Refrigerate leftovers.