1. Preheat oven to 350°F. Line 12 muffin tins with paper liners.
2. Sift the flour, baking soda and salt in a bowl. Add the sugar, buttermilk, oil and vanilla and stir to combine (do not overmix).
3. Fill each baking cup 2/3 full. Bake until a skewer inserted into the middle of a cupcake comes out clean, about 20 minutes. Allow the cupcakes to cool for 5 minutes before removing them from the pan.
For the lemon glaze:
1. In the bowl of an electric mixer fitted with a paddle attachment, combine the confectioner?s sugar and egg white. Beat on low speed until the mixture is smooth, about 5 minutes. With the mixer running, gradually add the water. Stir in the lemon oil.
2. Using a small spoon, spread the glaze on top of the cooled cupcakes. Store the cupcakes in an airtight container.
Makes 12 standard sized cupcakes or 24 miniature cupcakes.