Preheat the oven to 180°C (Gas Mark 4 / 350°F).
Cut the broccoli into several rough chunks, and add to a food processor. Blitz until no lumps remain. Transfer the broccoli to a large mixing bowl, and add the eggs, garlic powder, onion granules, and plenty of salt and pepper. Mix well.
Line two baking trays with non-stick paper, and thoroughly spray with oil, then divide the broccoli mixture onto the two trays. Use the back of a spoon to carefully spread the broccoli mixture into the shape of two pizza crusts, smoothing over any holes that appear.
Bake the broccoli pizza crusts for around 25-30 minutes, or until firm and starting to turn golden brown (the exact timings will depend on how thin you made your pizza crusts).
Use a spatula to make sure the crust isn't stuck to the paper. Then, add some grated cheese and your choice of toppings. Return to the oven for a further 20 minutes, or until the cheese is melted and slightly crispy.