In a pan, drizzle oil and heat over medium-high heat. Add the sliced onions and stir for a few minutes.

Lower the heat and stir occasionally to prevent burning. Add a splash of water as needed to keep the onions from sticking. Cook for about 30 minutes until caramelized. Set aside.

Butterfly the hot dog lengthwise. Heat it in a pan until browned.

Toast the buns in the same pan until golden.

Spread cream cheese on the inside of the bun.

Place the hot dog inside the bun, then top with caramelized onions, sliced jalapeños, and ketchup.