Preheat oven to 350°. Line the two standard cupcake tins with ice cream cones and set aside.
With electric mixer, beat the butter on a medium speed until creamy.
Add the granulated sugar and vegetable oil until well-combined and creamy.
Scrape down the sides of the bowl and fold in the vanilla extract.
In a separate mixing bowl, whisk together the flour, baking powder and salt. Measure out milk.
With the mixer on a medium speed, gradually alternate between adding the flour mixture and the milk to the butter mixture, starting and ending with the flour mixture. Stir until each one is almost completely combined before adding the next. Scrape down sides of the bowl as needed.
In another mixing bowl, combine egg whites and with a hand mixer on high speed, beat until stiff peaks form.
Using a spatula, gently fold your egg whites into your batter. Take care to scrape the sides and bottom of the bowl so that the ingredients are well-combined, do not overmix.
Divide the cupcake batter among 6 different bowls and add food coloring to each bowl to get desired intensity. Layer each ice cream cone with about 1-2 tsp of each color, until it is about ¾ full.
Bake them for 25 minutes or until cupcake comes out clean with knife.