Lay out cauliflower on a large baking sheet. Drizzle with olive oil and season with salt and pepper. Use your hands to toss and coat all of the pieces well, then spread them out on the sheet.
Roast for 35-40 minutes, tossing halfway through. They should be soft and just starting to brown. Remove from the oven, sprinkle generously with the almond flour and use tongs or utensils to toss to coat. Return to the oven for 10 minutes longer. To serve, taste and add additional salt and pepper as needed.