Move a rack in the oven to an upper position (the first or second one) then preheat it to 450ºF (232ºC). Line a large baking sheet with parchment paper. Set aside.
Pour the olive oil, salt, garlic powder, black pepper, and onion powder into a large zip-top bag or large container with a tight-fitting lid. Add the cauliflower, seal the bag or container, and shake until everything is evenly coated.
Spread the cauliflower out onto the prepared baking sheet, but don't discard the bag or container. Bake the cauliflower for 10 minutes, then remove from the oven and turn the cauliflower pieces over (as best as you can). Return the baking sheet to the oven and bake another 10 minutes.
Add the hot sauce to the bag or container. When the cauliflower is finished with its second bake, add it to the bag or container with the hot sauce and gently turn or stir to coat. While the baking sheet is empty, dab off the excess moisture from the parchment paper.
Return the coated cauliflower to the baking sheet (I used a slotted spoon to reduce exceess sauce) and bake for another 10 minutes. While the cauliflower bakes, prepare the slaw.
In a large bowl, toss together the coleslaw mix and the cilantro until evenly dispersed. Add the lime juice or white vinegar, mayonnaise, and granulated sugar, and stir until everything is coated.
Taste the slaw and add salt and pepper as needed. I added about ¼ teaspoon of each.
ASSEMBLE THE TACOS
Heat the tortillas in a hot skillet, 10-15 seconds per side.
Fill each taco with the buffalo cauliflower and top with cilantro slaw. Serve immediately. Store cauliflower and cilantro separately, covered tightly, in the refrigerator for up to 3 days. Reheat cauliflower in a toaster oven, in a large skillet over medium-high heat, or in the microwave.