National Pizza Day

The interior of a pizza birthday cake.

Pepperoni and Sausage Pizza Bread Pudding

PHOTO:Pizzadilla

PHOTO:Pizza Birthday Cake

PHOTO: Pizza Croutons

PHOTO: Pizza Soup

PHOTO: Grilled Cheese Crust Pizza

PHOTO: A pizza doughnut from Dough Exchange in Santa Ana, Calif.

PHOTO: Rachael Ray's Matzo-Pizza Lasagna

PHOTO: Champagne went into the dough of this luxe mushroom pizza.

Sonoma Flatbreads by Donatos offers authentic restaurant-style pizza for gluten-free consumers. (PRNewsFoto/Sonoma Flatbreads)

The Bajalieh Special at Slice Pizza & Brew in Birmingham, Ala., is topped with bacon, grilled red onions and Wickles Wicked Pepper Rings. (Birmingham News file/Michelle Campbell)