Wash and core 10 strawberries. Set aside.
Preheat oven to 325 degrees. Line a cupcake tray with 10 liners. Set aside.
In a medium bowl, sift together cake flour, baking powder, baking soda, and salt. Set aside.
Into the bowl of an electric stand mixer add butter and vegetable oil. Cream together butter and vegetable oil until completely combined (2-3 minutes). Scrape down the sides of the bowl
With the mixer on low speed, gradually pour in sugar. Turn mixer to medium to high and mix until light and fluffy 1-2 minutes
With the mixer on low speed, add in egg whites one at a time. Allow each to combine before adding in the next. Add in vanilla extract mix until combined.
Scrape down the sides of the bowl. With the mixer on low speed, add one third of the flour mixture into the bowl and mix until just combined.
Scrape down the bowl and add one half of the butter milk and again mix until just combined. Repeat this process. Begin and end with the flour mixture.
Do not over mix or your cupcakes will become quite dense.
Spoon approximately 2 tablespoon of batter into bottom of cupcake liners.
Place cored strawberry standing up into the bottom of each cupcake liner.
Spoon batter around strawberry and on top. Bake for 18-20 minutes. Allow to cool completely before frosting.