Mix all ingredients well in a large bowl. Spread evenly on a baking sheet lined with parchment paper.
Place in the preheated oven on the middle shelf for 20 - 30 minutes. Stir once halfway through with a spatula. If you want small lumps, press everything down again with the spatula.
Turn off the oven and loosen the granola a little with a fork. Close the oven again and let the granola dry in the oven for about 15 minutes. Take out and let cool down completely.
The granola can then be refined as you like, e.g. with desiccated coconut, chocolate pieces or dried berries. I prefer to eat it straight.
Perfect as muesli, with yoghurt or just for snacking!