Preheat the oven to 450˚F.
Divide the dough into four and roll, toss or press each into an 8-10 inch circle. Place on two floured or parchment-lined baking sheets.
Meanwhile, cook the bacon in a skillet until crisp, adding the baby spinach to the pan for the last minute of cooking, so that it just wilts.
Spread tomato sauce over each pizza crust and top with the bacon-spinach mixture and mozzarella cheese.
Bake for 8-10 minutes, until the pizzas are pale golden.
Remove from the oven and crack an egg onto the surface of each pizza; return to the oven for 6-7 minutes, until the eggs are just set, but the yolks are still runny.