• Preheat the oven to 325 degrees F. Grease and flour three 8 inch pans, adding a circle of parchment or wax paper to the bottom of each pan.
• In a medium bowl, whisk the flour, baking powder, baking soda, and salt for 30 seconds and set aside.
• In another bowl, add the champagne, vegetable oil, and vanilla extract. Set aside.
• In the bowl of your mixer, add the butter and cream cheese and mix at medium speed until smooth.
• Gradually add the sugar and mix at medium speed for 2-3 minutes.
• Add the room temperature eggs one at a time, mixing after each until the yellow of the yolk has blended.
• With the mixer on low speed, alternately add the flour mixture and the champagne mixture, beginning and ending with the flour mixture (We did 3 additions of the dry mixture, 2 additions of wet)
• Mix the batter just until well combined- be careful not to over-mix. Divide the batter between the three pans.
• Bake at 325 degrees F for 25-28 minutes or until a toothpick inserted into the center comes out clean or with just a few crumbs attached. Let cool for 5-10 minutes in the pans on a wire rack before turning out.
• This recipe makes 7 ½ cups of batter. Works for cupcakes also (although there will be little to no dome).

For the Champagne Simple Syrup

• Combine the champagne and sugar in a microwave safe measuring cup or bowl. Heat for 30 seconds, stir, and then if then if needed, an additional 30 seconds. Stir to melt any remaining sugar. We did this in the microwave but you could heat in a small saucepan on the stovetop if you prefer, until the sugar dissolves.

For the Sweetened Whipped Cream Filling

• Chill the mixing bowl and beaters/ whisk attachment in the freezer for 10 minutes.
• Pour the whipping cream, powdered sugar and vanilla extract into the chilled mixing bowl, begin beating on low speed gradually increasing to medium high speed.  
• The cream will begin to thicken (after approx. 1 ½ minutes). Keep mixing until stiff peaks form- be careful not to overmix. This happens fairly quickly. You've reached "stiff peak" stage, when you can lift the beaters from the whipped cream and the resulting peaks hold their shape.

For the Champagne Buttercream

• Cream the (slightly softened) butter until smooth. Blend in the vanilla.
• Add half of the powdered sugar and most of the champagne. Beat at medium speed until the powdered sugar is incorporated.
• Add remaining powdered sugar and champagne and mix at medium speed another 3 to 4 minutes, stopping to scrape down the sides of the bowl occasionally with a spatula. Then, slow down the mixer to lowest speed for 1-2 minutes. This will help eliminate air pockets in the buttercream. The texture will become very smooth.
• Yields approximately 4 ½-5 cups of frosting. Enough to frost a 3 layer 8 or two layer 9 inch cake.
• If your buttercream is too thin, add more sugar. If the consistency is too thick, add a bit more champagne

Assembly of Cake

• Place the first layer of champagne cake on a cake base or pedestal.
• Using a pastry brush, apply a thin layer of champagne syrup to the top of the cake layer. (Once the cake is assembled, you'll likely have some simple syrup leftover- we did.)
• Pipe a dam of buttercream around the edge of the layer, about ¼-1/2 inch from the edge. You can do this using a disposable piping bag with the tip snipped away (creating an opening approx ½ inch wide).
• Spread the whipped cream filling inside of the dam of buttercream. (If you are not using a dam, just make sure that your filling is a good distance from the edge of the cake layers (approx ½ inch) to ensure the whipped cream won't escape as you stack your layers).
• Add the next cake layer and repeat steps for filling. Top with the last cake layer. Fill in any remaining gaps between the cake layers with buttercream (I do this with the same piping bag that I used for the dam.)
• Add a thin "crumb coat" on top and around the sides of the cake. At this point, we like to freeze the cake for about 15 minutes (or chill for a longer period in the refrigerator) to firm up the frosting before adding the final coat. This step helps to prevent the layers from shifting as you decorate the cake.
• Apply the final coat of buttercream frosting, decorate however you like! We used a cake comb around the sides and added borders with a star tip 21.

Storage

• Because of the filling, this cake should be refrigerated in an airtight container under a cake dome or in a sealed bakery box, etc. However, it is best to move from the refrigerator a couple of hours before serving so that the cake can warm and soften, as butter becomes firm when refrigerated.