Muesli is made from oatmeal, combined with nuts, seeds, dried, and possibly other grains. No sweetener is added. Granola contains fat (oil or butter) and sugar. This is baked in the oven, making it crispy and sweet. Then you can mix it with nuts, dark chocolate chunks, dried fruit, chia seeds, pumpkin seeds, etc. Don't add fresh fruit (add it just before serving; otherwise you can't store your granola that long). The result: a crunchy granola mixture.