enough homemade or store-bought pizza dough, for 1 large pizza, or 6 ready-made, pre-baked individual pizza shells
shredded mozzarella, or Monterey jack
cooked ground beef
cooked chicken breast, cut in chunks
cooked bacon, crumbled
olives, (green and/or black), sliced
fresh tomato, chopped
hot pepper rings
First, arrange all the toppings (choose as many as you like) in individual bowls. The younger your sleepover guests are, the fewer choices you will have to offer - don't worry, they'll be happy with whatever you give them.
Preheat the oven to 425°F (220°C). Grease a cookie sheet or two (depending on how many pizzas you'll be making).
Next, if you're using ready-made, pre-baked pizza shells, simply hand one to each child and turn them loose with the toppings. If you're using homemade or store-bought pizza dough, divide it into 6 pieces and let everyone roll out her own dough on a floured surface to about 6 in. (15 cm) in diameter. This can be a messy process, so if you'd prefer to avoid the chaos, roll the dough out yourself ahead of time and just let the kids put on the toppings. Words of advice: sauce first (not too much), cheese next, veggies and other lumpy bits on top.
Place the finished masterpieces on a well-greased cookie sheet and, if you're using dough as a base, leave room between them for expansion (pre-baked crusts won't spread out). Place pans on the lowest oven rack and bake for 10 (for pre-baked crusts) to 20 minutes (raw dough), or until the crusts are lightly browned underneath, the toppings are heated and cheese is bubbling.