Combine brown sugar, paprika, ground mustard, 1 teaspoon salt, ½ teaspoon black pepper, garlic powder, and cayenne pepper in a small bowl until well blended.
Brush pork tenderloin with 1 tablespoon olive oil to coat; rub spice mixture on all sides of tenderloin and let sit for 5 minutes.
Preheat an air fryer to 400 degrees F (200 degrees C) according to manufacturer's instructions.
Carefully place tenderloin in air fryer basket; cook in the preheated air fryer for 20 minutes.
Meanwhile, place broccoli in a microwave-safe bowl. Microwave on high until tender, about 3 minutes. Stir in 1 tablespoon olive oil; season with salt and black pepper.
Transfer tenderloin to a cutting board; rest before slicing, 10 minutes.
Meanwhile, place broccoli in air fryer basket. Cook in the air fryer 10 minutes, shaking basket halfway through.