Preheat the oven to 160C/325F and line a baking tray with grease proof paper/a silicone mat.
Place the oats, cinnamon, raisins and diced apple into a large bowl and toss to combine.
Add in the vegetable oil, applesauce, maple syrup and vanilla extract and stir until all of the oats are coated in the liquid. Some large lumps may form, this is fine.
Tip the mixture onto your prepared pan an spread into an even layer.
Place in the oven for 35-45 minutes until golden all over and firm to the touch. Every 15 minutes, give the mixture a quick stir/turn to make sure it browns evenly.
Once cooked, leave to cool on the tray completely. Once cool, store in an airtight container, at room temperature, for a week.
You can serve this granola with milk, yoghurt, fruit or alone as a quick snack!