In a large bowl, whisk flour, sugar, baking powder, baking soda and ground cinnamon.
Add butter, egg whites, milk and vanilla essence and mix on medium speed.
In a separate small bowl, mix ground cinnamon and the light brown sugar.
With cupcake liners, line the cupcake tray.
Preheat the oven to 160°C or 350 degrees Fahrenheit.
Place 1 tablespoon of batter into the cupcake liner.
Sprinkle 1/4 teaspoon of the cinnamon and sugar mixture on top of the batter.
Add another tablespoon of the batter. *Sprinkle a little cinnamon on top of the batter if you like.
Repeat steps 6, 7, and 8 until the cupcake liners are filled with batter.
Bake the cupcakes at 160°C for 16-18 minutes or until a toothpick comes out with a few crumbs.
Leave the cupcakes in a cooling rack to cool and begin making the icing.
To make the icing: beat the butter until smooth and slowly add the powdered sugar and mix until combined.
Mix the ground cinnamon and 1/2 teaspoon of vanilla.
Mix the icing batter till you get the right consistency and then ice the cupcakes. Sprinkle a little ground cinnamon on top of the icing sugar.