Preheat oven and line cupcake tin. Preheat your oven to 180°C (350°F) and line 12 hole cupcake pan with paper liners.
Mix dry ingredients together. In a large bowl, add the cake flour (or plain/all-purpose flour & cornflour if you are substituting the cake flour with them - see notes below for quantities). Also add white and brown sugar, baking powder and baking soda, cinnamon, cloves, nutmeg, ginger and salt and whisk together.
Add the fats and mix. Add the butter and oil into the bowl and mix together on medium speed using hand-held electric beaters. If the mixture looks a bit lumpy, don't worry!
Add eggs whites and mix. Add in your egg whites and beat again until mixed in.
Add in wet ingredients. With the beaters running on low, add in the vanilla extract, sour cream, then milk and beat until just combined.
Scoop into cupcake liners and bake. Divide the batter evenly between the 12 cupcake paper liners- the batter should reach ⅔ full. Bake for 20 minutes or until the sponge is golden and springs back when gently pressed in the middle.
Cool and core the cupcake center. Leave cupcakes in the pan for ten minutes before removing and cooling completely on a wire rack. Once cooled, use a small spoon, paring knife or apple corer to remove a small amount of sponge from the center of the cupcake. Don't go all the way to the bottom, only a 1 cm (¼ inch) deep holes are needed.