PREPARE THE OATMEAL CRUMBLE
1. Preheat oven to 350°F (180°C). Line a small baking sheet with parchment paper.
2. In a bowl, toss together rolled oats, chopped hazelnuts, brown sugar, melted coconut oil, cinnamon, and salt until everything is evenly coated.
3. Spread the mixture in a thin, even layer on the prepared baking sheet. Bake for 8–10 minutes, stirring once halfway through, until the oats are golden and the hazelnuts are fragrant. Watch carefully in the final minutes — the crumble goes from perfectly toasted to burnt in seconds.
4. Remove from oven and let cool completely on the tray. The crumble will crisp further as it cools. Break apart any large clumps for a mixture of fine and coarse pieces. Set aside.
5. Increase oven temperature to 425°F (220°C) for the tarts.

PREPARE THE TART MOULDS
6. Generously butter four 4-oz (120 ml) ramekins or dariole moulds. Dust with cocoa powder, tapping out excess. This double coating ensures a clean release when the tarts are inverted. Place prepared moulds on a baking sheet and refrigerate until needed.

MAKE THE MOLTEN CHOCOLATE BATTER
7. SET UP A BAIN-MARIE: Place a heatproof bowl over a saucepan of gently simmering water, ensuring the base of the bowl does not touch the water. Add chopped dark chocolate and cubed butter. Stir occasionally until fully melted and combined into a smooth, glossy mixture. Remove from heat and let cool for 3–4 minutes — warm but not hot.
8. WHISK THE EGGS: In a separate bowl, whisk together whole eggs, egg yolks, and sugar until the mixture is pale, slightly thickened, and the sugar has dissolved — about 2 minutes of vigorous hand whisking or 1 minute with an electric whisk. You want a cohesive, slightly foamy mixture, not full ribbon stage.
9. COMBINE: Pour the melted chocolate-butter mixture into the egg mixture, add vanilla extract, and fold gently but thoroughly with a spatula until no streaks remain.
10. ADD FLOUR: Sift in the flour and salt, then fold until just incorporated. Do not overmix — a few tiny flour specks are preferable to overworking the batter, which develops gluten and makes the tarts cakey rather than molten.
11. FILL THE MOULDS: Divide the batter evenly among the prepared moulds, filling them about three-quarters full. Filled moulds can rest at room temperature for up to 30 minutes while you prepare the cranachan cream.

BAKE THE TARTS
12. Place the baking sheet with filled moulds in the preheated 425°F (220°C) oven. Bake for exactly 6–8 minutes. The tarts are done when the edges and top are set and slightly puffed, but the very centre still has a visible wobble when you gently shake the tray. If you touch the centre lightly, it should feel soft like a barely-set custard.
13. Do not overbake. It is far better to pull them 30 seconds early than 30 seconds late. An overbaked tart is just a chocolate cake; a perfectly baked one is a revelation.
14. Remove from oven and let stand for exactly 60 seconds. Run a small knife around the edge of each mould, place a serving plate over the top, and invert confidently in one smooth motion. Lift the mould away.

MAKE THE CRANACHAN CREAM
15. CRUSH THE RASPBERRIES: Set aside 4–6 of the best-looking raspberries for garnish. Lightly crush the remainder with a fork — some structure remaining, not a smooth purée. A few whole berries mixed with jammy, broken-down fruit creates the ideal texture.
16. WHIP THE CREAM: In a chilled bowl, whip the cold heavy cream to soft peaks — the cream should hold gentle mounds when the whisk is lifted but still look billowy and relaxed, not stiff or grainy.
17. FOLD IN THE CRANACHAN ELEMENTS: Drizzle in the whisky and honey, then fold gently until just combined. Fold in the crushed raspberries, creating a rippled, marbled effect — streaks of raspberry pink through the cream. Taste and adjust: more honey for sweetness, more whisky for warmth.
18. Keep the cranachan cream cold until plating.

PLATE AND SERVE
19. Assemble immediately after unmoulding. Place each warm inverted tart slightly off-centre on the plate. Add a generous spoonful or quenelle of cranachan cream on top of the tart or alongside it. Scatter the toasted oatmeal crumble over and around the tart.
20. Garnish with reserved fresh raspberries, a light drizzle of heather honey, and the faintest dusting of icing sugar if desired.
21. Serve immediately. The molten centre gives approximately 2–3 minutes of flowing chocolate before it begins to set.