Preheat oven to 400°. Line 9 muffin cups with foil liners or grease 9 nonstick muffin cups.
In a small bowl, combine muffin mix, milk and egg; stir in hot dogs, cheese and, if desired, jalapeno. Fill prepared cups three-fourths full.
Bake until a toothpick inserted in center comes out clean, 14-18 minutes. Cool 5 minutes before removing from pan to a wire rack. Serve warm. Refrigerate leftovers. Freeze option: Freeze cooled muffins in freezer containers. To use, microwave each muffin on high until heated through, 30-60 seconds.