Having trouble finding cost effective rolled oats? Look for Quaker Rolled Oats in the cereal aisle.
Bonus: If you are making granola and you want big chunks, pack all your ingredients tightly together on a baking sheet (I find it easier on a lipped baking sheet but plain should work fine). Once the granola is baked and cooled, you can break it into chunks.
A recent paper published in Nature Materials details a theory that seeks to explain how wrinkles form on curved surfaces, along with an accompanying prediction equation. The more curved a surface is, note the researchers, the more like it is to have a regular, often hexagonal, pattern. On thinner surfaces, however, curvature plays less of a role and the expected regimented pattern is increasingly broken up and more random.