Heat oil in a large pot or deep fryer to 325°F; fry potatoes in batches 5 minutes until soft but not browned. Remove; drain on paper towels.
Increase oil to 375°F; fry again in batches 3-4 minutes until golden brown and crispy. Drain; immediately season with salt and pepper.
Arrange hot fries on a large oven-safe platter or baking sheet; drizzle with warm cheese sauce.
Sprinkle with cheddar and bacon; broil 1-2 minutes until cheese melts.
Remove; top with sour cream dollops, green onions, and optional jalapeños. Serve immediately, hot.