Combine the coriander, cumin, paprika, thyme, oregano, brown sugar, cocoa powder, lemon juice, chili powder, garlic powder, dried chile pepper, cinnamon, nutmeg, salt, and pepper in a small bowl.
Spread 2 tablespoons of olive oil on each side of the bison ribeye steaks.
Use your hands to rub the prepared seasoning mixture into the steaks, ensuring they are evenly coated. Drizzle over more olive oil.
Let the steaks rest until they reach nearly room temperature.
Heat a grill pan or grill over medium-high heat.
Sear both sides of the steaks for 2-4 minutes to achieve grill lines.
Check the internal temperature of the steaks using a meat thermometer. The steaks are ready when the internal temperature reaches 120°F.
Remove the steaks from the heat and let them rest for 10 minutes before slicing.
Serve the spicy cowboy bison steaks alongside some oven-baked corn and mini crab cakes. Enjoy!