Preheat the oven to 450°F and line a large baking sheet with parchment paper.
Cut the cauliflower into florets and place on the baking sheet. Toss with 2 tablespoons olive oil and 2 teaspoons salt.
Bake until slightly browned and tender, about 25 minutes, tossing once halfway through.
Make lemon tahini dressing by combining tahini, lemon, salt, garlic powder, and ½ cup warm water and whisk together. Add an additional ¼ cup warm water if you prefer a thinner dressing.
Remove cauliflower from the oven and transfer to a platter. Add chopped dates, pistachios, fresh mint and lemon tahini dressing and toss together and serve.