Preheat the oven to 375°F/190°C/Gas Mark 5, no fan.
Clean the raspberries with a wet paper towel, set aside.
Prepare a muffin pan (standard size) and line it with 12 paper liners. Spray the liners with a non-stick baking spray (optional).
Add the eggs, yogurt, butter, sugar, lemon zest, vanilla, baking powder, baking soda, and salt into a large bowl. Whisk until well combined.
Add the flour, fold in with a spatula until just combined.
Add the raspberries and white chocolate chopped into small chunks, fold in gently with a spatula until evenly distributed and there are no streaks of flour visible. Don’t overmix the batter.
Divide the batter evenly between 12 muffin liners. There will be lots of batter in each muffin liner, they will be overfilled - this is fine!
Make the crumb topping: add the flour, soft butter, and brown sugar into a medium bowl. Rub the ingredients with your fingers. The mixture should be forming crumbs and hold together when pinched. Sprinkle the topping over the muffin batter.
Bake for about 25 minutes, take the pan out of the oven, let rest for 1 minute then test with a wooden skewer/toothpick/cake tester - it should come out clean, without raw batter on the tester.
Place on a cooling rack to cool slightly then enjoy!