01 - Preheat the oven to 375°F. Line a 12-cup muffin tin with paper liners or grease lightly with cooking spray.
02 - In a large bowl, whisk together flour, sugar, baking powder, baking soda, and salt until evenly combined.
03 - In a separate bowl, whisk the eggs, oil, yogurt (or sour cream), lemon zest, lemon juice, and vanilla until smooth and well blended.
04 - Pour the wet ingredients into the dry ingredients. Gently fold together with a spatula until just combined; do not overmix as this will make the muffins tough.
05 - Toss the raspberries with 1 tablespoon flour in a small bowl to prevent them from sinking. Gently fold the coated raspberries into the batter.
06 - Divide the batter evenly among the muffin cups, filling each about 3/4 full. Use an ice cream scoop for consistent portions.
07 - Bake for 18 to 22 minutes, or until a toothpick inserted into the center of a muffin comes out clean or with just a few moist crumbs.
08 - Let muffins cool in the pan for 5 minutes before transferring to a wire rack to cool completely.