Step 1: Preheat oven to 180C.
Step 2: Peel, core and slice the apples into wedges and place in a medium saucepan.
Step 3: Add the lemon zest, brown sugar, butter, cinnamon sticks and Verjuice. Bring to a gentle simmer, and continue to cook until tender but not mushy (about 20 minutes). Check to see that apple wedges are cooked through.
Step 4: Remove the apples from the saucepan, discarding the cinnamon and lemon zest, and arrange in the base of an oven proof dish.
To make the crumble:
Step 5: Mix together the brown sugar, wholemeal flour, oats and ground cinnamon in a mixing bowl.
Step 6: Using a vegetable grater, grate the butter onto the flour mixture, and incorporate using the tips of your fingers until mixed like course breadcrumbs.
Step 7: Top the apples with the crumble mixture and bake in the oven preheated for 30 minutes, until the crumble is golden brown.
Step 8: Allow to cool slightly then serve with Rich Vanilla Bean Ice Cream or runny cream.