Heat oven to 175C and line a 20x20cm baking tin with greaseproof paper.
Whisk together extra virgin olive oil, maple syrup and egg in a large mixing bowl.
Add oats, spelt, almond meal, cinnamon and baking powder and mix.
In a separate bowl toss diced apple with cinnamon, maple syrup, tahini and lemon juice.
Spread ⅔ of the oat mix into the base of the tin and press down lightly.
Then add the apple mixture over the top.
Crumble the remaining oat mixture over the top of the apple (in small pieces is best) and press all down lightly.
Bake in oven for 35-40 minutes, or until the top crumble is lightly golden.
Cool completely in the tin before slicing.
Store up to 2 days in an airtight container or up to 5 days in the fridge.
