Preheat the oven to 350°.
Spread the almonds on a pie plate and toast for 10 to 12 minutes, until golden. Let cool, then coarsely chop. Increase the oven temperature to 425°.
Meanwhile, in a saucepan, combine the lentils with 2 cups of water and bring to a boil. Simmer over moderate heat until tender, 20 minutes. Drain well and let cool.
On a large rimmed baking sheet, toss the cauliflower with the 1/4 cup of olive oil and the cumin, cinnamon, ginger and cayenne; season with salt and pepper. Roast for 20 minutes, turning, until the cauliflower is tender and golden brown.
In a large bowl, whisk the tahini with the lemon juice, honey, the remaining 1 tablespoon of olive oil and 2 tablespoons of water until smooth.
Add the lentils and season with salt and pepper; toss to coat.
Scrape the roasted cauliflower into the bowl and add the toasted almonds, dates, onion and spinach. Toss the salad, transfer to a platter and serve.