Quick cooking oats are an ingredient that I like to use a lot in baking, and they frequently show up in my recipes for oatmeal cookies and cakes. Quick cooking oats are rolled oats that have been coarsely chopped into smaller pieces to allow them to cook more quickly than regular oatmeal. Usually, they’re about 1/4 or 1/3 the size of a regular rolled oatmeal flake. They are larger than instant oatmeal, which tends to have a very powdery consistency.
Quick cooking oats, which are sometimes labeled “1-minute oats” on packaging, aren’t as prominent as regular rolled oats are when used in a recipe. Cookies that use them, for instance, will typically have a more uniform consistency and appearance. They also may be slightly less chewy (although this depends a lot on the baking time) than cookies made with the thicker whole rolled oats. Cakes made with quick cooking oats will typically have a finer, tighter crumb to them. In all cases, recipes that use quick cooking oats will have just as much flavor as those made with regular rolled oats, so it all comes down to a matter of personal preference in the end.
You can turn regular rolled oats into the quick cooking variety by pulsing them a few times in the food process to break them up.