Preheat the oven to 350 degrees. Line a cupcake pan with liners (or spray with non-stick spray), set aside.
Cream together the softened butter and sugar until well combined.
Add in the liquid ingredients - the separated egg whites (discard the yolks or save for a custard, creme brulee, etc), the milk, vanilla and oil. Thoroughly mix the ingredients - stopping the mixer and scraping the sides occasionally to ensure everything gets mixed in.
In a separate bowl, combine the dry ingredients - flour, salt and baking powder - and whisk.
Combine the dry ingredients with the mixing bowl containing the butter and liquid ingredients. Stir on low speed for about a minute. Stop the mixer and scrape down the sides. Continue to mix on medium speed for about another minute until the mixture is well combined.
Using just one cup of the chocolate chips, add them to the cake batter, reserving the remaining chocolate chips for decoration.
Fill each cupcake cavity until about ⅔ full of cupcake batter. Should get approximately 30 regular sized cupcakes.
Bake for approximately 14-16 minutes or until slightly golden brown and the middle of each cupcake is set.
Allow baked cupcakes to cool to the touch before decorating.