Slightly thaw the frozen pizza so you can cut into slices.
Have pre-cut semi-frozen slices ready to go on a baking sheet or parchment paper before your guests arrive.
Preheat oven to 450 degrees.
Set up table with small bowls of each topping.
At the beginning of the bar, provide guests with paper plates so they can add toppings to their pizza slices.
At the end of the bar, have several baking sheets lined with parchment paper ready for the oven.
When guests are done, have them place a slice on the parchment paper and write their name next to it with a pencil or sharpie marker.
Bake a pan full of pizza slices for about 5 minutes or until brown.
Place baking sheet on table with a spatula for guest to grab their slice.