01 -
Preheat your oven to 350°F (180°C) conventional or 320°F (160°C) fan/convection. Line a 12-cup muffin tin with paper liners.
02 -
In a large bowl, combine the flour, sugar, baking powder, and vanilla sugar with a wooden spoon. If you're using chocolate chips, add them to this dry mixture now.
03 -
In a separate bowl, use a hand mixer or stand mixer to combine the eggs, oil, and sour cream until smooth and uniform. If you're adding lemon juice or other liquid flavorings, mix them in at this stage.
04 -
Add the dry ingredients to the wet mixture. Mix briefly - only 20-30 seconds! The batter should be relatively thick, not creamy. Overmixing will prevent your muffins from being light and fluffy.
05 -
Gently fold in your chosen fruit with a wooden spoon. If using frozen berries, don't worry if the batter changes color slightly - this is completely normal.
06 -
Immediately distribute the batter evenly among the 12 muffin cups using two tablespoons or an ice cream scoop. Fill cups completely for large, domed muffins, or about 2/3 full for smaller ones.
07 -
Bake on the middle rack of your preheated oven for 25-30 minutes. Check for doneness by inserting a wooden toothpick into the center of a muffin - it should come out clean.
08 -
Keep your freshly baked muffins in an airtight container for up to two days. They also freeze beautifully and can be thawed at room temperature whenever a muffin craving strikes.