Preheat oven to 375°F (190°C). Position rack in center of oven. Butter or spray with a non-stick cooking spray 12 muffin cups. Set aside.: When you open the oven later, you should smell warm metal and faint residual heat if it is properly preheated. Preheating ensures the muffins get an immediate temperature shock that encourages rise, creating those tender domes we love. A common mistake is not preheating, which leads to flat, dense muffins; always allow the oven to reach temperature. Also, placing the rack in the center promotes even browning and avoids overly dark bottoms or undercooked centers. If using a convection oven, consider a slightly lower setting or shorter time, because circulating air browns faster.
In a large measuring cup or bowl whisk together the egg, buttermilk, oil, Meyer lemon juice and vanilla extract.: Right away you should notice the glossy sheen as the oil and egg combine, and the mixture will smell faintly of citrus and vanilla. Whisking ensures even distribution of the acid from the Meyer lemon with the buttermilk , which activates the baking soda later. Avoid over-whisking until foamy, because that can introduce too much air and produce an uneven crumb. If your wet mix separates, a quick final whisk before folding will bring it back together.
In another large bowl combine the flour, sugar, baking powder, baking soda, salt, and lemon zest. Gently fold in the berries. With a rubber spatula fold the wet ingredients into the dry ingredients and stir only until the ingredients are combined. Do not over mix the batter or tough muffins will result.: As you stir, the lemon zest releases fragrant oils, perfuming the dry mix and making it smell bright. Folding the chopped strawberries into the dry ingredients before adding the wet mix helps keep them suspended rather than sinking to the bottom. A common error is stirring the berries too vigorously, which can bruise them and cause bleeding into the batter; fold gently to maintain texture and color. If your berries are wet, pat them dry to reduce added moisture that could make the batter runny.
Fill each muffin cup almost full of batter, using two spoons or an ice cream scoop. Place in the oven and bake until a toothpick inserted in the center of a muffin comes out clean, about 20 minutes. Transfer to a wire rack and let cool for about 5 minutes before removing from pan.: You should see streaks of pale batter disappear into a slightly lumpy, cohesive mix, with chunks of fruit dotted throughout. The batter will be thicker than pancake batter but still scoopable. Overmixing activates gluten, producing a chewy, tough texture, so stop when you can no longer see dry streaks. If you notice large pockets of flour, gently press with the spatula to incorporate, rather than beating, which preserves tenderness. The sound should be quiet, with no splattering or sloshing.
Fill each muffin cup almost full of batter, using two spoons or an ice cream scoop. Place in the oven and bake until a toothpick inserted in the center of a muffin comes out clean, about 20 minutes.: As you portion the batter, the bowls will feel warm and the batter should be thick enough to mound slightly in each cup. Using an ice cream scoop helps create uniformly sized tops and consistent baking. During baking, you will smell citrus lifting and notice the tops turning a light golden brown and doming. Insert a toothpick in the center near the end of the time window, if it comes out with a few moist crumbs it is done; raw batter indicates more time is needed. A common misstep is assuming color alone denotes doneness, when underbaked muffins can be brown but still raw inside.
Transfer to a wire rack and let cool for about 5 minutes before removing from pan.: The muffins will still be gently steaming, and the aroma will be at its most intense. Cooling on a wire rack prevents soggy bottoms by allowing air circulation, and the short rest helps the crumb set so they remove cleanly from the tin. Avoid removing them immediately, which can cause them to break apart, and do not leave them in the hot pan for too long, which traps steam and softens the crust. If a muffin sticks, run a thin knife around the edge to help release it without tearing.