First, add 1 1/2 cups of Brut champagne to a sauce pan on the stove over high heat. Once the champagne starts to boil, turn the heat down to medium so it maintains a rapid simmer. When the liquid has reduced to 1/4 cup worth, (after about 15-25 minutes), remove the champagne from the heat and set aside.
Preheat your oven to 350°F/177°C. Then, line two cupcake pans with 20 paper or silicone cupcake liners. Note - you may not need them all. Set those pans aside for now.
Next, in a small bowl, add all of the WET ingredients. Set this bowl aside, too.
In a medium-sized mixing bowl, add the DRY ingredients. Stir well to combine.
Add half of the WET ingredients to the DRY ingredients and give it a stir. Then, add the other half and stir again, scraping down the sides as necessary.
Finally, add the 1/4 cup of reduced champagne AS WELL AS two tablespoons of champagne straight from the bottle. Give that batter one final stir until it is smooth and silky and dreamy.
Add batter to each cupcake liner only until it's about 2/3 full. Over filling leads to overflowing cupcakes, which can ruin your cupcakes! Use a retractable ice cream scoop to make the process easier.
Bake these babies in your preheated oven for 19-20 minutes or until a toothpick inserted down the center of each cupcake comes out clean and free of batter. When they're cool enough to handle, transfer them to a cooling rack to finish cooling.
In the meantime, make your frosting. Start by beating the shortening on high using a hand or stand mixer until creamed, about 30 seconds to a minute.
Then, add the salt, half of the powdered sugar and 3 Tbsp. of the champagne to the bowl. Mix on a LOW speed until mostly combined. Repeat with the second half of sugar and remaining 2 Tbsp. champagne.
Finally, crank your mixer to a HIGH speed and whip that frosting until it's super light and fluffy, about 30 seconds or so.
When your cupcakes are completely cooled, frost them using a piping bag fitted with a tip, or, go the old fashioned route and frost using a butter knife. Garnish the tops with festive sprinkles, if you so desire! (THIS is where I got mine.)