preheat the oven to 325 degrees
line two cupcake baking pans with paper liners and set aside
place the champagne in a saucepan and simmer and let it reduce until there’s only ¾ cup of liquid remaining.
cool the reduced champagne
reserve 1-2 Tablespoons for the buttercream frosting be sure to set it aside before pouring the rest into the cake mix
in a small bowl, measure and whisk together flour, baking powder, salt and set aside.
in a separate bowl or the bowl of a stand mixer, beat butter and vanilla together until smooth and creamy
add sugar, vegetable oil, and eggs, mixing until combined
set the mixer to medium speed, gradually alternating between adding flour mixture and concentrated liquid champagne.
stir until each one is almost completely combined before adding the next, scrape down the sides and bottom of the bowl as you work
fill cupcake liners ¾ full
bake for 18-20 minutes
cool on a wire rack for an hour or until cool
meanwhile make the buttercream
in a large bowl, using an electric mixer, beat butter, powdered sugar, vanilla and 1-2 tablespoons of the champagne reduction until smooth
drizzle in milk as needed to reach desired consistency for piping
drop a piping tip in a piping bag and place it tip down in a large cup easing the bag open over the cup
fill the bag with frosting
when cupcakes are cool frost with large swirls of frosting and add sprinkles or foil as desired