To Make Cupcakes

1. 1-Preheat the oven to 350°F. Line two 12-well muffin tins with paper cupcake liners and set aside.

   2-In a large mixing bowl, sift together the flour, baking powder, and salt; whisk to ensure the dry ingredients are well combined. Set aside.

   3-Add the eggs to the bowl of a stand mixer fitted with the paddle attachment. Add 1¾ cups of sugar mix eggs and the vanilla extract and mix on medium speed for 1 minute. Reduce the mixer speed to low and add the oil in a slow, steady stream until it’s incorporated into the egg mixture. 

   4-Add a third of the flour mixture to the mixer bowl and stir until just barely blended. Add half the Champagne and stir until just barely blended. Repeat. At this point, the batter should be thin. Turn the motor off and stir in the last third of the flour mixture by hand, with a rubber spatula, to ensure you don’t over mix the batter (this would result in tough cupcakes).

   5-Divide the batter evenly between the 24 paper-lined muffin wells. Bake for 10 minutes. Rotate the muffin tins in the oven and bake 10 to 15 minutes more, until a toothpick inserted in the center of the cupcakes comes out clean. Transfer the muffin tins to wire racks for the cupcakes to cool.

To make the filling:

1. 1-Place a fine sieve over a mixing bowl and set aside. Heat the half and half in a medium heavy-bottomed saucepan over low heat until hot but not boiling. Meanwhile, in a mixing bowl, beat the egg yolks, sugar, and a pinch of salt until combined. Add the Champagne and whisk to combine, followed by the cornstarch. Mix a third of the heated half and half into the egg yolk mixture while whisking. Pour the entire mixture back into the saucepan and cook over medium heat, stirring constantly with a wooden spoon or heat-proof spatula, until the mixture begins to thicken.

   2-Immediately strain the mixture through the sieve and into the mixing bowl. Add the butter and vanilla extract and whisk until combined. Place plastic wrap directly on top of the custard to avoid a skin from forming and allow to cool in the refrigerator for at least 1 hour (can be made up to 2 days ahead). 

To Assemble

1. 1-To make the whipped cream frosting, add the chilled cream to the bowl of a stand mixer fitted with the whisk attachment. Begin to whip at medium speed. When the whisk begins to leave tracks in the cream, add the sugar. Increase the speed to medium-high and whip until the cream holds a medium-firm peak. Add ½ cup of the chilled filling and whip into the cream for a few seconds more.

   2-Scrape the filling into a pastry bag fitted with a small tip. (Alternately, add the filling to a zipper-top bag and snip off the corner, through which you can pipe the filling.) Using a small spoon or melon baler inserted in the top, remove the center of each cupcake (the scooped insides make great snacks while decorating!). Pipe each center core with the custard filling. 

   3-Transfer the whipped cream to a pastry bag fitted with a star tip. Pipe whipped cream on the top of each cupcake and sprinkle with the gold dust.