01 - Preheat oven to 450°F. Place pizza stone in oven if using.
02 - Roll pizza dough out on a floured surface to a 12-inch round. Transfer to a parchment-lined baking sheet or pizza peel.
03 - Evenly spread crème fraîche or sour cream over dough, leaving a 1/2-inch border.
04 - Sprinkle mozzarella and cheddar cheeses evenly over sauce.
05 - Distribute bacon or sausage, cherry tomatoes, red onion, and spinach over the cheese.
06 - Create 4 wells in the toppings using a spoon, and carefully crack an egg into each well.
07 - Season with salt and pepper. Bake for 12 to 15 minutes, until crust is golden and eggs are just set. For firmer yolks, extend baking time.
08 - Remove from oven. Sprinkle with fresh chives, if desired. Slice and serve immediately.