1. Preheat oven to 350 degrees and line pans with cupcake liners.
2. In a large bowl, gently combine eggs, egg whites and oil.
3. Add buttermilk, sour cream and vanilla. Mix.
4. Add cake mix (for easy mixing, sift in) and stir until combined.
5. Fill cupcake liners ¾ full and bake for 16-20 minutes or until an inserted knife comes out clean.
6. Once cupcakes are nearly cool, make ganache.
7. White Chocolate Ganache: Use a microwave or double boiler to heat white chocolate chips and heavy cream and stir until smooth. Be careful not to burn the white chocolate.
8. Dip the tops of the cupcake in the ganache.
9. Buttercream: Beat cream cheese, butter and zest until light and fluffy, it should take about 4 minutes. Slowly add powdered sugar until you reach your desired consistency. If you need to loosen the buttercream, add a tablespoon of orange juice.
10. Pipe onto cupcakes once the ganache has set and top with sprinkles. I used a 1M tip and used a rosette piping technique.