Rub tenderloin with bbq rub then wrap with bacon slices using toothpicks to secure ends.
Bake in a glass dish for 1 hour, on the middle rack, flipping tenderloin half way through (so the bacon doesn’t get soggy).
Turn oven to broil (staying at 350°) move pan to bottom rack and broil 20 minutes, turning tenderloin half way through.
When tenderloin reaches and internal temperature of 155°-160° move dish back to middle rack, and paint tenderloin with bbq sauce. Broil for 5 minutes, then flip tenderloin, paint other side, and broil another 5 minutes.
Let rest 5-10 minutes then slice into medallions, serve with bbq sauce.