01 - Preheat your oven to 400°F. Line a baking sheet with parchment paper to prevent sticking.
02 - Carefully remove the outer leaves from the cauliflower. Trim the stem, ensuring the main head remains intact. Rinse the cauliflower under cold water and pat it thoroughly dry with paper towels.
03 - In a small bowl, combine the olive oil, ground cumin, smoked paprika, garlic powder, 1/2 teaspoon salt, and 1/4 teaspoon black pepper. Mix well until a paste forms.
04 - Place the prepared cauliflower onto the parchment-lined baking sheet. Using a pastry brush or your hands, evenly apply the spice mixture all over the entire cauliflower head, ensuring full coverage.
05 - Roast the cauliflower for 45 to 55 minutes, or until it is golden brown, fork-tender, and easily pierced with a knife. If you notice the cauliflower browning too quickly, loosely tent it with aluminum foil.
06 - While the cauliflower roasts, prepare the drizzle. In another small bowl, whisk together the tahini, fresh lemon juice, maple syrup or agave, finely grated garlic clove, 1/4 teaspoon salt, and 3 tablespoons of cold water. Continue whisking, gradually adding more cold water, 1 tablespoon at a time, until the sauce reaches a smooth, pourable consistency.
07 - Once roasted, carefully transfer the whole cauliflower to a serving platter. Drizzle generously with the prepared tahini-lemon sauce.
08 - Sprinkle the roasted cauliflower with chopped fresh parsley and toasted sesame seeds. Serve immediately, with lemon wedges on the side if desired.