Grate a lemon until you have enough rind. One batch is about half of a normal sized lemon.
Combine the sugar and lemon rind and set aside.
Muffins
Wash and dry your blueberries, looking over them to make sure all of the stems are removed. Set aside
Add all of the dry ingredients into a large bowl. Separately combine all of the wet ingredients, egg, milk, and butter, in a 2 cup measure. Add the wet ingredients all at once to the dry ingredients.
Add half of the topping to the batter. Stir lightly, only until the ingredients are mixed. Light mixing is the secret to fluffiness of the muffins! Add the berries just before all of the flour is incorporated, folding in gently.
Spoon the bater into a greased muffin pan, filling about 2/3 full. These muffins will rise!
Sprinkle a spoon-full of topping onto each muffin, using it all up.
Bate at 425F for 20 minutes, or until golden brown.