Physical principles are involved in almost any aspect of cooking. Here we analyse the specific process of baking pizzas, deriving in simple terms the baking times for two different situations: for a brick oven in a pizzeria and a modern metallic oven at home. Our study is based on fundamental thermodynamic principles relevant to the cooking process and is accessible to undergraduate students. We illustrate the underlying physics by some simple common examples and then apply them in detail to the example of baking pizza.