Take a medium-size bowl, add brown sugar, garlic powder, black pepper, onion powder, smoked paprika, kosher salt, and white sugar to it. Whisk the mixture well and rub it all over the beef.
Smoke the beef in a pre-heated (250 F) smoker for about 4 hours until the internal temperature of the beef reaches 165 F. Now, remove it from the smoker and keep it aside for 10-15 minutes.
Prepare the sauce by mixing BBQ sauce, brown sugar, and honey in a bowl. Apply the sauce to the beef after cutting it into cubes. Put them in the foil pan and add more sauce to it. Stir well until it combines.
Place the pan back on the smoker and smoke the beef for 1 hour until the cubes get tender.