1. Heat the olive oil in a saucepan over medium heat. Add the chopped onions and cook until they are soft and translucent.
2. Add the tomato sauce, mustard, garlic powder, onion powder, smoked paprika, salt, and black pepper. Stir well to combine and let it simmer for about 10 minutes.
3. In a frying pan, cook the vegan hot dog sausages according to the package instructions.
4. Place the cooked sausages in the hot dog buns. Top with the prepared sauce and serve immediately.