Preheat your grill to medium-high heat. In a large bowl, combine the cauliflower florets, olive oil, chili powder, cumin, garlic powder, smoked paprika, salt, and pepper. Toss until the cauliflower is evenly coated.
Place the cauliflower on the grill and cook for about 10-12 minutes, turning occasionally, until tender and slightly charred.
While the cauliflower is grilling, warm the corn tortillas on the grill for about 1 minute on each side, or until they are pliable.
Once the cauliflower is done, remove it from the grill and chop it into smaller pieces if desired.
Assemble the tacos by placing a generous amount of grilled cauliflower on each tortilla. Top with shredded red cabbage, avocado slices, and fresh cilantro.
Serve with lime wedges on the side for squeezing over the tacos.