How to Make It
Set a pizza stone on the bottom of the oven and set a rack on the top shelf. Preheat the oven to 500° and heat the stone for at least 45 minutes. In a food processor, combine the crumbled graham crackers with the brown and granulated sugars and the butter, vanilla and salt. Process the mixture to fine crumbs.
On a lightly floured work surface, roll out each piece of pizza dough to a 12-inch round. Transfer 1 round of dough to a lightly floured pizza peel. Very lightly drizzle the round with vegetable oil and gently rub the oil over the dough.
Slide the dough onto the hot stone and bake for about 2 minutes, until it starts to brown on the bottom and puff on top. Using 2 large spatulas, remove the pizza crust and sprinkle it with half of the graham cracker crumbs, half of the chocolate and half of the marshmallows. Return the pizza to the stone and bake for 1 minute. Transfer the pizza to the top shelf of the oven and bake for about 1 minute, until the marshmallows are browned.
Sift confectioners' sugar on top. Cut the pizza into wedges and serve right away. Repeat with the remaining dough, oil, graham cracker crumbs, chocolate and marshmallows to make a second pizza.