Preheat your air fryer to 320°F (160°C) for about 3 minutes. This ensures it's at the right temperature when you're ready to bake.
Using a hand blender, cream the softened butter and caster sugar together until you achieve a smooth and fluffy consistency.
Beat in the egg until it is fully incorporated before mixing in the vanilla bean paste or extract for a delightful aroma.
Stir in the plain natural yogurt and the semi-skimmed or full-fat milk.
In a separate bowl, combine the self-raising flour and salt.
Gradually add the dry mixture to the wet ingredients, and fold gently until everything is well combined without overmixing it.
Carefully fold the white chocolate pieces into the batter.
Line your silicone muffin cups with paper liners or lightly grease them. I use a 7-cup mini muffin mold that fits perfectly to my air fryer but you can use full-size individual muffin cups. You might need to bake your muffins in 2-3 batches.
Fill each cup about two-thirds full with batter to allow room for rising and add a couple of raspberries on top.
Place the filled muffin cups in the air fryer basket, ensuring they don't touch each other to allow proper air circulation.
Air fry the muffins at 320°F (160°C) for 10 minutes. Check for doneness by inserting a toothpick into the center of a muffin; if it comes out clean, they're ready. If you use normal muffin cups, you will need to bake them for another 3-4 minutes.
Once done, carefully remove the muffins from the air fryer and let them cool in the cups for a few minutes before transferring them to a serving plate.