- Preheat oven to 356F (180C).
- Mix all the ingredients for the streusel with your hands until crumbly and set aside.
- In a large bowl, beat the eggs, yogurt, milk, butter, zest and sugar with a mixer. Separately mix the flour and baking powder and add to beaten ingredients. Mix until smooth.
- Add the raspberries to the batter and mix gently.
- Grease the baking molds with butter, sprinkle with flour (or use muffin paper) and fill 3/4 full. Sprinkle with streusel on top.
- Bake for 25-30 minutes until golden brown (dry toothpick).