Spread pine nuts on a rimmed baking sheet and toast, tossing once, until golden, about 6 to 8 minutes (watch carefully as they burn easily); set aside.
Increase oven temperature to 450 degrees F.
Toss cauliflower florets with the cayenne, 2 tablespoons of the oil, 1/2 teaspoon salt, and 1/4 teaspoon black pepper; roast, tossing once, until tender and golden, about 20 minutes, depending on the size of your florets.
Meanwhile, use a large bowl and whisk together the tahini, lemon juice, remaining 2 tablespoons of oil, water, 1/4 teaspoon salt, and 1/4 teaspoon pepper (add more water if needed to achieve the consistency of heavy cream).
To the bowl, add the kale, onion, raisins, pine nuts, and cauliflower; toss to combine and serve.