In a small mixing bowl, combine the brown sugar, salt, cumin, garlic powder, onion powder, turmeric powder, smoked paprika, and black pepper. Stir until well incorporated. Store in an airtight container.
To use the rub, pat dry the steak with a paper towel.
Liberally sprinkle the rub over the steak and gently rub the seasoning in using your fingers. Refrigerate at least 30 minutes or overnight.