1. Prepare your dough ahead of time.
2. Fire up your Ooni Pizza Oven.
3. Lightly dust your peel with flour or fine semolina then stretch out the dough to anywhere from 12 to 14 inches and lay it on your peel.
4. Drizzle the pizza base with a little olive oil starting from the outside in, then sprinkle the dark chocolate evenly over the dough.
5. Slide the pizza off the peel and into the oven.
6. Immediately top the pizza with marshmallows and return it to the oven to finish cooking for another 30 to 60 seconds, turning regularly.
7. Finish the cooked pizza with crushed graham crackers.