Prepare the crumble topping. In a small bowl, rub the cold butter into the flour, brown sugar, and cinnamon using your fingertips until the mixture resembles coarse, sandy breadcrumbs with a few pea-sized lumps. The texture should feel cool and crumbly, not wet. Pop it in the fridge to stay cold while you work on the batter.

Toss the peaches. In a separate bowl, gently mix the diced peaches with the cornflour until every piece is lightly coated. You’ll see the flour turn slightly translucent against the fruit. This step is crucial—it will thicken their juices as they bake, preventing a soggy muffin.

Whisk the dry ingredients. In a large bowl, whisk together the plain flour, golden caster sugar, baking powder, bicarbonate of soda, salt, cinnamon, and nutmeg. The aroma that rises is warm and inviting, a promise of the spice to come.

Combine the wet ingredients. In a jug, beat the buttermilk, vegetable oil, eggs, and vanilla extract until they are fully combined and look pale and slightly frothy on top.

Make the muffin batter. Pour the wet mixture into the dry ingredients. Stir gently with a wooden spoon or spatula, just until you can no longer see streaks of flour. The batter will be thick, lumpy, and slightly shaggy—do not overmix, or the muffins will be tough.

Fold in the fruit. Gently fold the cornflour-coated peaches into the batter. You want them evenly distributed, but the batter will still look a little rustic. You’ll see small, jewel-like pieces of peach peeking through.

Assemble the muffins. Line a 12-hole muffin tin with paper cases. Divide the batter evenly among the cases—they should be nearly full to the top. Then, generously sprinkle the chilled crumble topping over each one, pressing it down very lightly. The top should look like a snowy, buttery landscape.

Bake to golden perfection. Bake at 200°C (180°C fan) for 22–25 minutes. The kitchen will fill with the scent of toasted butter and caramelised fruit. The muffins are done when the tops are a deep golden brown, the crumble is crisp, and a skewer inserted into the centre comes out with a few moist crumbs (not wet batter).

Cool and present. Let the muffins cool in the tin for 5 minutes—you’ll hear a faint crackling sound as they settle. Transfer them to a wire rack. Once fully cool, give them a light dusting of icing sugar for that final, polished look.