Preheat oven to 180 degrees Celsius - fan-forced (355 degrees fahrenheit).
Line a 12-hole muffin tin with paper cases and set aside until needed.
Sift the self-raising flour into a large bowl.
Add the caster sugar and stir together.
Create a well in the centre of the dry mixture.
In a separate bowl, lightly beat the egg before adding the vegetable oil and milk and whisking together until well combined.
Pour the liquid ingredients into the well in the dry ingredients, and very gently fold the mixture together. The batter should be slightly lumpy; don't over-mix.
Very gently fold through the raspberries and white chocolate chunks, don't over-mix as you don't want to break up the raspberries.
Spoon the mixture into the paper cases, filling ⅔ to the top.
Bake for 20-25 minutes or until lightly golden.
Allow to cool in the baking tray for 5 minutes before transferring to a wire rack to cool completely.