Air fryers are a time saver, but in return, you’ll need to give up a big chunk of counter space. If your kitchen is on the small side, this can be a problem. When you already have a microwave, kettle and toaster on the countertop – and then add an air fryer – it can leave you little room for food preparation. Enter Ninja’s Double Stack air fryer, which aims to solve this problem with a build that stacks two cooking drawers one on top of the other (as you may have guessed by the product name) instead of side by side, as with the Ninja Foodi Max Dual Zone. Ninja doubles down on its space-saving …