Preheat the oven to 170°C. Prepare a deep heatproof bowl that can go into the oven.
Slice up the peaches and mix them with sugar, cinnamon, lemon juice, and a pinch of salt. Make sure the spices are everywhere. Pour the peaches into the bowl and bake for 20 minutes.
In the meantime prepare a crumble mixture. Add flour, oil, and sugar into the bowl and mix well with a fork. The mixture should crumble, so add ingredients until it's perfect. I recommend using a very small amount of crumble mixture on the peaches - the dessert is very sweet.
In another bowl prepare oats. Mix oats, cinnamon, maple syrup or honey, coconut oil, vanilla extract, and nuts. You can add more honey or maple syrup so they stick together.
When you take the baked peaches out of the oven, sprinkle a little amount of crumble mixture over them with chunks of oats. Bake for another 20 - 35 minutes. Check on the dessert if the oats or crumble aren't getting too brown.
Take the peach crumble out of the oven and let cool. Serve with ice cream.