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 mixing bowl, whisk together flour, sugar, baking powder, baking soda, and salt until evenly distributed.
03 - In a separate bowl, whisk the eggs, oil, yogurt or sour cream, lemon zest, lemon juice, and vanilla extract until smooth and well blended.
04 - Pour the wet ingredients into the dry ingredients. Using a spatula, gently fold together until just combined. The batter should remain slightly lumpy—do not overmix.
05 - Place fresh raspberries in a small bowl and toss with 1 tablespoon flour to coat evenly. This prevents berries from sinking to the bottom during baking.
06 - Gently fold the flour-coated raspberries into the batter, taking care not to crush them.
07 - Divide the batter evenly among the prepared muffin cups, filling each about 3/4 full.
08 - Bake for 18 to 22 minutes, or until a toothpick inserted into the center comes out clean or with just a few moist crumbs attached.
09 - Allow muffins to cool in the pan for 5 minutes, then carefully transfer to a wire rack to cool completely before serving.