Whisk together the brown sugar, chili powder, smoked paprika, kosher salt, cumin, dried mustard, dried thyme, dried oregano, garlic powder, onion powder, and freshly cracked black pepper together in a bowl.
Pour into a glass jar and seal with an airtight lid. Store in a dark cool place.
To use, sprinkle the meat with a liberal amount of seasoning and rub it in. Be sure to cover the entire surface of all sides of the meat.
Allow the meat to rest with the seasoning in the refrigerator for at least 2 hours up to overnight. Cook the meat as desired. Enjoy.