1. To make the champagne reduction used in the cupcakes, filling and frosting, add all of the champagne to a medium sized saucepan and cook over medium heat until you’ve got 1 cup remaining. Don’t boil. To measure how much champagne remains, pour into a glass measuring cup. Add it back to the pan if it needs longer to cook down. When done, refrigerate until cool.
2. To make the filling, put the white chocolate chips in a medium sized bowl.
3. Put the champagne reduction and heavy whipping cream in a microwave safe measuring cup or bowl and microwave until it begins to boil.
4. Pour the cream over the white chocolate chips and allow to sit for 2-3 minutes, then whisk until smooth. If needed, microwave the mixture for 10-20 more seconds, then whisk until smooth.
5. Set the ganache in the fridge to firm up, about 2-3 hours.
6. To make the cupcakes, prepare a cupcake pan with cupcake liners and preheat the oven to 350°F (176°C).
7. Combine the flour, baking powder and salt in a medium sized bowl and set aside.
8. Add the butter, sugar and oil to a large mixer bowl and beat together until light in color and fluffy, about 3 minutes. Do not skimp on the creaming time.
9. Add the eggs one at a time, mixing until mostly combined after each. Add the vanilla extract with the second egg. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated.
10. Add half of the dry ingredients to the batter and mix until mostly combined.
11. Slowly add the milk and champagne and mix until well combined. The batter might look a little curdled, but that’s ok.
12. Add the remaining dry ingredients and mix until well combined and smooth. Scrape down the sides of the bowl as needed to be sure all ingredients are well incorporated. Do not over mix the batter.
13. Fill the cupcake liners about 3/4 full and bake for 14-16 minutes or until a toothpick inserted into the center comes out clean.
14. Remove cupcakes from the oven and place on a cooling rack to cool.
15. While the cupcakes cool, finish the filling. Put the chilled mixture in the bowl of a mixer and whip with the whisk attachment until soft peaks form, about 5-7 minutes. You’ll notice the mixture lighten in color.
16. Cut out the centers of the cupcakes. You can use a cupcake corer or a knife.
17. Fill the centers of the cupcakes with the filling. Set the cupcakes in the fridge while you make the frosting.
18. To make the frosting, combine the butter and shortening in a large mixer bowl and beat until smooth.
19. Add about half of the powdered sugar and mix until smooth and well combined.
20. Add 3 tablespoons of the champagne reduction and the salt to the frosting and mix until well combined.
21. Add the remaining powdered sugar and mix until smooth. Add additional champagne reduction as needed to get the right consistency.
22. Pipe the frosting onto the cupcakes. I used Ateco tip 844. To see how to create the rosette design, see my cupcake frosting tutorial.
23. Sprinkle the edges of the frosting with sprinkles, if desired.
24. Refrigerate cupcakes until ready to serve. Serve cool, but not cold. Cupcakes are best if eaten within 2-3 days.