Top with marshmallows and return to oven for about 5 minutes to finish baking the crust. The marshmallows should start to puff and brown, but if they aren't done to your liking, simply place under the broiler for 1-2 minutes (watch carefully so you don't burn them!) Remove from oven.
In a small bowl, microwave the chocolate chips and coconut oil in intervals of 30 seconds. Stir to completely melt the chocolate and mix in the oil.
Drizzle the chocolate over the pizza and slice with a pizza cutter. Serve warm with a big glass of milk, because this dessert is RICH!