(15.25-ounce) box vanilla or white cake mix sparkling sparkling wine (such as champagne, prosecco or cava), at room temperature large eggs vegetable oil For the Champagne Buttercream: Tip: The cake ...

(15.25-ounce) box vanilla or white cake mix For the cake: Preheat the oven to 350°F. Spray a 13-by-9-inch baking pan with baking spray and line with parchment paper. Line a second baking sheet ...