Preheat and Prep: First, preheat your oven to 180°C (160°C fan). Choose a baking dish that will hold the four apples snugly without them touching. A 20cm (8-inch) square dish is ideal.

Prepare the Apples: Wash and dry your apples. Using an apple corer or a small, sharp knife, carefully remove the core from each apple, stopping about 1.5cm from the bottom. You want to create a cavity for the filling, not a tunnel! I find a melon baller is excellent for scooping out any remaining seeds neatly.

Score the Apples: To prevent the skins from splitting during baking, use the tip of a sharp knife to score a thin line around the circumference (the 'equator') of each apple.

Make the Filling: In a medium mixing bowl, combine the rolled oats, chopped pecans, light brown sugar, cinnamon, nutmeg, and the pinch of salt. Add the cold, cubed butter.

Combine the Filling: Using your fingertips, rub the butter into the oat mixture until it resembles coarse breadcrumbs. Don't overwork it; a few small lumps of butter are fine. Stir in the teaspoon of lemon juice.

Stuff the Apples: Pack the oat mixture firmly into the cavity of each apple, mounding it slightly on top. Place the stuffed apples into your prepared baking dish.

Create the Sauce: In a small jug, whisk together the maple syrup and water. Pour this liquid into the baking dish, around the base of the apples. Dot the top of each apple's filling with a tiny piece of the remaining 15g of butter.

Bake to Perfection: Place the dish in the preheated oven and bake for 45-50 minutes. About halfway through, I like to open the oven and carefully spoon some of the pan juices over the apples. This helps them stay moist and builds a lovely glaze.

Check for Doneness: The apples are ready when they are tender all the way through (a skewer or sharp knife should slide in with little resistance) and the filling is golden brown. The sauce in the dish should be bubbling and slightly thickened.

Rest and Serve: Carefully remove the dish from the oven and let it stand for 5-10 minutes before serving. This allows the molten-hot filling to cool slightly. Serve the apples warm, with a generous spoonful of the maple sauce from the bottom of the dish drizzled over the top.