You Don't Always Need To Preheat Your Oven For Baked Pasta. Here's Why
Forgot to preheat the oven in the stressful rush of assembling a batch of baked ziti for a bunch of hungry kids? Don't panic. You can simply place it in the cold oven anyway, switch it on, and continue prepping the other parts of your meal. While preheating the oven is normally the first step to preparing virtually any baked pasta recipe, it isn't always necessary when preparing dishes like lasagna, cannelloni, or stuffed shells. These classics will still cook to perfection as the oven comes to temperature without it adversely affecting the texture of the noodles or meltiness of a gooey cheese topping.
Of course, skipping the preheating stage will increase the overall cooking time of your dish, in the same way that baking a chilled lasagna (that you've prepared ahead of time) will take longer to cook than a freshly made room-temperature one. However, this issue is offset with some key benefits. Firstly, the extra time it takes for the oven to reach the correct temperature provides the optimum conditions for the flavors in your dish to meld. For example, the noodles have more opportunity to imbibe the garlicky aroma of your marinara, and the béchamel can evenly settle into every nook and cranny of a generous layer of ground beef, encouraging each element to bubble together beautifully. Your mozzarella and cheddar topping will also have plenty of bandwidth to melt gently and develop an appetizing cheese pull without burning.
Finish off your pasta dish with a blast under a hot grill
When baking a traditional lasagna Bolognese, the cheese on the top surface can bubble and blacken before the dried pasta sheets layered into the dish have had enough time to cook through and become al dente. Ready-to-bake dried noodles don't require pre-boiling, but they do need time to soak up the moisture in the layers to become pliable and soft. Starting your pasta off in an un-preheated oven eliminates this problem as the cheese can melt slowly without developing a charred crust, while the pasta cooks to the perfect texture. However, if you enjoy a bubbly, crunchy crust, simply turn on the grill function of your oven at the end of the cook time to allow the top to become golden and crisp.
Having said all this, preheating the oven is a must when baking other items, such as muffins and breads, because the leavening agents in these baked goods require the immediate burst of heat from the oven to give them a powerful lift. Placing these items in a cold oven will hamper their rising capabilities, resulting in flat, stodgy cakes. The same can be said for egg-based dishes, such as quiches, tarts and soufflés that require that extra heat to trap the air and encourage a fluffy texture.