Preheat the oven to 180 °C (160 °C fan) and wash the apples. Core them and cut them into small cubes.
Put the diced apple in a small baking dish and sprinkle with some of the cinnamon.
Roughly chop the walnuts. In a bowl, mix the buckwheat flour, coconut oil, walnuts, the rest of the cinnamon and the maple syrup into a loose crumble.
Spread the crumble evenly over the apples so everything is well covered.
Bake the crumble at 180 °C for 20–25 minutes, until the topping is golden brown and the apples are soft.
Serve the crumble warm, ideally shortly after baking.
Good to know
When the kitchen smells of warm cinnamon and baked apples, it instantly feels cosy. This crumble is simple, crunchy and just right for days when you want something easy from the oven.
Swaps
Walnuts → pecans (similarly nutty, milder in flavour). Buckwheat flour → oat flour (more soluble fibre). Maple syrup → date paste (more fibre, less free sugar per spoonful).
Allergens
Contains tree nuts (walnuts). With finely diced, soft-baked apples it's usually child-friendly, and it's unremarkable during pregnancy as long as all ingredients are fresh and well heated.