Preheat your oven to 425°F (220°C). This high temperature at the beginning helps create that perfect muffin dome. Line 12 standard muffin cups with paper liners or spray them with nonstick cooking spray to prevent sticking.
In a large mixing bowl, combine lemon zest, granulated sugar, and light brown sugar. Use your fingertips to mix the ingredients together until the sugar feels moistened and fragrant. This step is crucial as it infuses the sugar with the lemon flavor.
Next, to the sugar mixture, add all-purpose flour, baking soda, and fine sea salt. Whisk these dry ingredients together until they are evenly mixed.
In another bowl, beat the egg lightly before adding fresh lemon juice, buttermilk, and vegetable oil. Mix until everything is well combined.
Create a small well in the center of the dry ingredients and pour the wet mixture into it. Stir gently just until combined; be careful not to overmix. The batter should be lumpy but well integrated.
Gently fold in the fresh raspberries, being cautious so they don’t break apart too much. This will ensure you get those lovely bursts of flavor in every bite.
Divide the batter evenly among the prepared muffin wells. The wells will be quite full, which is what we want for a nice dome shape.
Sprinkle the tops with coarse sugar for a sweet, crunchy topping. This adds a delightful texture to the muffins.
Now, bake the muffins in the preheated oven for 10 minutes. After that time, without opening the oven door, reduce the temperature to 350°F (175°C) and bake for an additional 7 to 9 minutes. You know they are done when the tops are golden brown and a toothpick inserted into the center comes out clean.
Once baked, let the muffins cool in the pan for about 5 minutes. Then, carefully transfer them to a wire rack to cool completely. This cooling step helps maintain their fluffy texture.
