Preheat and prepare: Set your oven to 220°C (200°C fan). Line a 12-hole muffin tin with paper cases — use tall, tulip-style cases if you want that professional bakery look. The paper should extend slightly above the tin rim to support a high dome.

Whisk dry ingredients: In a large bowl, whisk together the flour, granulated sugar, baking powder, bicarbonate of soda and salt until evenly combined. The mixture should look pale and feel light and powdery between your fingers — no clumps of baking powder visible.

Combine wet ingredients: In a separate jug, whisk the vegetable oil, eggs, buttermilk, vanilla extract, orange zest and orange juice until the mixture is smooth and pale yellow, with tiny flecks of zest suspended throughout. It should smell fragrantly of citrus, not eggy.

Fold wet into dry: Pour the wet mixture into the dry ingredients. Use a rubber spatula to fold gently — only 10 to 12 strokes. Stop when you see a few streaks of flour remaining; the batter should look shaggy and lumpy, not smooth. Over-mixing here will create tough, dense muffins.

Add the cranberries: Gently fold in the cranberries with 2 to 3 additional strokes. If using frozen berries, the batter may turn slightly pink around the edges — that's fine. The berries should be evenly distributed but not crushed; you'll see bright red jewels peeking through the pale batter.

Rest the batter: Cover the bowl with a clean tea towel and let it rest at room temperature for exactly 15 minutes. This allows the starches to hydrate and the gluten to relax, creating a more tender crumb and a taller rise. You'll notice the batter thickens slightly and looks more cohesive.

Fill and top: Use a large ice cream scoop or two spoons to divide the batter evenly among the 12 cases, filling each to the very top — about ¾ full for standard cases, or almost full for tulip cases. The batter should be mounded slightly above the rim. Sprinkle each generously with turbinado sugar; the coarse crystals should form a visible, glittering crust.

Bake at high heat: Place the tin in the oven and bake at 220°C for 5 minutes. This initial blast of heat sets the dome. Then, without opening the door, reduce the temperature to 190°C (170°C fan) and bake for another 13–17 minutes. The muffins are done when the tops are deep golden brown, spring back firmly when pressed, and a skewer inserted into the centre (avoiding a berry) comes out clean with just a few moist crumbs. The kitchen will smell of toasted sugar and warm orange.

Cool properly: Remove the tin from the oven and let it sit on a wire rack for 5 minutes. Then lift each muffin out of the tin and place directly on the rack to cool completely. If you leave them in the tin too long, the steam will make the bottoms soggy and the domes will deflate slightly. The paper cases should peel away cleanly once completely cool.