Heat oven to 400°F. Line a sheet pan or have an oven-safe skillet ready.
Cook bacon in a skillet over medium heat until crisp, 6–8 minutes. Drain on paper towels; crumble.
Pat chicken dry. Mix salt, pepper, smoked paprika, and garlic powder. Rub chicken with olive oil, then the seasoning.
Sear chicken in the same skillet over medium-high heat until lightly browned, 2–3 minutes per side.
Transfer to the oven (skillet or sheet pan) and bake until 160°F in the thickest part, 12–15 minutes.
Brush each breast with barbecue sauce and bake 3–4 minutes to set the glaze.
Top with Monterey Jack, cheddar, and crumbled bacon. Broil 2–3 minutes until cheese melts and bubbles.
Rest 5 minutes. Scatter tomatoes, green onions, and parsley over the top. Serve hot.