Place the flank steak on a large cutting board. Using a sharp knife, carefully butterfly the steak horizontally, stopping before cutting all the way through. Open the steak like a book.
Cover the steak with plastic wrap and gently pound it to an even thickness of approximately ¼–⅓ inch.
Season the inside of the steak with the kosher salt, black pepper, smoked paprika and garlic powder.
In a small bowl, combine the softened cream cheese, diced jalapeños, green onions and minced garlic.
Spread the cream cheese mixture in a thin, even layer over the steak, leaving approximately a ½-inch border around the edges.
Sprinkle the pepper jack cheese and cooked bacon evenly over the cream cheese mixture.
Starting at one long edge, roll the flank steak tightly into a log.
Tie the steak roll securely with butcher’s twine at approximately 1½–2-inch intervals.
Using a sharp knife, carefully slice between each piece of twine to create individual steak pinwheels.
Brush the pinwheels lightly with olive oil and season the exposed steak with additional salt and pepper as desired.
Preheat the grill to medium-high heat. Place the pinwheels onto the hot grill and cook for approximately 3–5 minutes per side, depending on thickness and desired doneness.
Remove the steak pinwheels from the grill and allow them to rest for 5 minutes before serving.