In a mixer with paddle attachment, combine the dry ingredients for the dough and mix well. With the motor running add the water and oil and mix for 3 minutes until the mix is smooth. Transfer to an airtight container, cover with a lid and let sit at room temp for 5 hours.
Preheat your oven to 240C with your baking tray in the oven, that you want to bake your pizza on.
Tip the dough onto a generously floured bench and knead for a few seconds with the flour, using a little extra flour to help it come together to a smooth soft dough.
Using a rolling pin and re flour the bench, roll the dough to approx. 5mm-7mm thick and approx. 40cm x 25cm. It will be bigger than this but trim the dough to that size so it can fit onto a piece of baking paper that fits onto your oven tray (keep any trim in the fridge, covered for up to 3 days for another pizza).
Transfer the dough carefully to the baking paper on a bench. You can do by rolling the dough up around the rolling pin then unrolling across the baking paper. Spread the dough with the pesto then scatter the olives, tomatoes, baby spinach if using and cheese. Season lightly with salt and pepper and drizzle with a little olive oil before transferring the pizza, on the baking paper to the preheated baking tray and into the oven. Cook for 6 minutes approx. until the cheese is starting to brown but still moist.