Preheat the oven to 220°C/425°F (200°C fan-forced). The initial high heat helps the muffins rise.
Line a standard 12-hole muffin tin with paper cases.
Whisk the flour, baking powder, baking soda, and salt together in a large bowl.
Melt the butter. Whisk in the sugar, then the egg, milk, vanilla, and vinegar until smooth.
Pour the wet mixture into the dry ingredients and mix only until nearly combined. Gently fold in the raspberries and white chocolate chips; keep the batter lumpy and avoid crushing the berries.
Divide the batter between the cases, filling them to the top.
Bake immediately, turning the oven down to 200°C/390°F (180°C fan-forced). Bake for 22–23 minutes, until a toothpick inserted in the center comes out clean.
Cool in the tin for 10 minutes, then transfer to a rack for 20 minutes before serving.