Preheat and prepare: Set your oven to 220°C (200°C fan). Line your muffin tin with tulip liners—these will help create that tall, bakery-style dome. The paper should feel crisp and the metal of the tin hot to the touch by the time you’re ready to bake.

Mix the dry ingredients: In a large bowl, whisk together the flour, cocoa powder, caster sugar, baking powder, bicarbonate of soda, and salt. The mixture should be a deep, uniform brown, with no pale streaks of flour visible. The cocoa scent will be earthy and slightly bitter.

Combine the wet ingredients: In a separate jug, beat the eggs, then stir in the buttermilk, vegetable oil, vanilla extract, and the melted dark chocolate. The liquid should be glossy and smooth, with the chocolate fully integrated—no streaks remain. The aroma shifts to a sweet, creamy fragrance.

Make the batter: Pour the wet mixture into the dry ingredients and fold together using a rubber spatula. Stop as soon as the flour disappears; a few lumps are fine. The batter will be thick and sticky, almost like a brownie mixture, and will smell deeply of rich chocolate. Fold in the chocolate chips until evenly distributed—you should see occasional flecks of chip peeking through.

Fill the liners: Using a large ice cream scoop or two spoons, fill each liner to the very top—almost overflowing. The batter should mound above the rim; this is what creates the signature domed top. Smooth the tops gently with the back of a spoon.

Bake at high heat: Place the tin in the oven and bake at 220°C for 5 minutes. Do not open the door. After 5 minutes, reduce the temperature to 180°C (160°C fan) without removing the muffins. Continue baking for 12–15 minutes. You’ll know they’re done when the tops are cracked and glossy, and a skewer inserted into the centre comes out with a few moist crumbs—not wet batter. The kitchen will smell like a chocolatier’s workshop.

Cool and garnish: Leave the muffins in the tin for 5 minutes—the bottoms will be soft and fragile. Transfer them to a wire cooling rack. While still warm, brush the tops with a little melted butter for extra shine, then sprinkle with flaky sea salt. The salt will glisten against the dark surface, creating a professional finish.