Ingredients for the Cake Batter:
1½ cups cake flour, sifted
1½ cups all-purpose flour, sifted
1 tablespoon baking powder
½ teaspoon salt
1 cup (2 sticks) unsalted butter, room temperature
2 cups granulated sugar
1-2 drops red food coloring, optional (Start with 1 for a blush and work up)
5 large egg whites
¼ teaspoon cream of tartar
Ingredients for the Strawberry Mousse Filling:
2 cups heavy whipping cream
1 3.5 oz. box of instant vanilla pudding
1/2 cup strawberry jam
Ingredients for the Champagne Swiss Meringue Buttercream:
1/2 cup champagne
6 large egg whites
1 1/2 cups granulated sugar
1 3/4 cup unsalted butter, slightly cooler than room temperature, cubed
2 tsp. pure vanilla extract
1/8 tsp. salt
2-3 drops red food coloring, optional
Preheat oven to 350 degrees F. Prepare two 9 inch round layer cake pans by lightly greasing the bottom and sides of pans with shortening or cooking spray. You can flour the pan at this point, but ever since a near cake disaster with another recipe last year, I take the additional step of lining the bottom with parchment paper, greasing the top of the parchment paper, and then flour the inside of the pan.
In a medium mixing bowl, whisk together the cake flour, all purpose flour, baking powder, and salt. Set aside.
In a small mixing bowl, stir the champagne and milk together. If tinting cake pink, add a drop of food coloring to the liquid mixture. Set aside. The milk might appear to curdle and that's fine.
In a large bowl of an electric mixer (using the paddle attachment if using a stand mixer), cream the butter and sugar until light and fluffy. If you're not familiar with how to cream sugar and butter, the creaming technique is described below. Take your time with this one - it is so worth the extra few minutes to get a lighter, fluffier cake.
Creaming technique: Start by placing the butter in a bowl and with an electric mixer on medium speed, begin by beating the butter about 1 minute until it is smooth and light in color. With the mixer still on medium speed, slowly add the sugar to the butter one tablespoon at a time taking about 5 minutes to add all of the sugar, and beating until the butter and sugar are fully incorporated and the mixture is a pale yellow color with a fluffy texture. Stop the mixer occasionally to scrape down the bowl and paddle/beaters.
With the mixer on low speed, add about one third of the flour mixture to the creamed butter mixture. Mix just until the flour is almost completely blended. Scrape the bowl down and add about 1/2 of the champagne mixture, blending just until mixed. Scrape the bowl down again and continue alternating with the flour mixture and champagne mixture, ending with the last portion of the flour and mixing just until blended. If tinting the cake and the batter looks too light in color, add more red food coloring one drop at a time until color desired and mix just until blended. Set aside. The batter will be thick.
In another large mixing bowl and using clean beaters (or if using stand mixer, use whisk attachment), beat the egg whites with an electric mixer until foamy, add the cream of tartar, and continue beating until stiff peaks form. Using a large rubber spatula, gently fold about ¼ of the beaten egg whites into the batter to lighten the batter, and then fold the remaining egg whites in.
Spoon the batter evenly into the prepared pans and smooth the surface with the back of a large spoon. Bake 30 to 35 minutes or until a toothpick inserted in the center comes out clean. I check mine at around 26 minutes as sometimes they're done a few minutes earlier. Remove from oven and place pans on a wire cooling rack to cool for 15 minutes, then remove cake from the pans and place the cake on the wire cooling rack to finish cooling.
Strawberry Mousse Filling:
While cake is baking, make the mousse filling. Beat whipping cream in a bowl with an electric mixer (use whisk attachment with stand mixer) until it begins to thicken.
Add the instant pudding and beat just until thick. Add the strawberry jam and mix until blended. Keep refrigerated until ready to use.
Champagne Swiss Meringue Buttercream Frosting:
If you've never made a Swiss Meringue Buttercream frosting before, I recommend you go over to Sweetapolita's blog and read her tutorial on it. It's excellent. I use a standard recipe similar to hers and it is a great buttercream frosting to use for desserts that have to sit out for awhile like in a party situation. I'll take you through the basic steps for this frosting, but seriously, go read Sweetapolita's post if you aren't familiar with this kind of buttercream. She even takes you through some great troubleshooting tips if something goes wrong. I've never had a problem making this, but if I did, her post could be my frosting savior!
Reduce the champagne down to concentrate the flavors in a small amount of liquid: In a small saucepan over medium-high heat, add champagne and bring to boil. Boil, uncovered, until the champagne has reduced down to 2 tablespoons. Remove from heat. Amazingly enough, reduced champagne tastes like...grape juice! :) Set aside to cool.
In a metal bowl (your metal bowl of your stand mixer is great if you have that), wipe out the bowl with lemon juice and paper towel to remove any trace of grease. Any spot of grease will reduce the volume of the egg whites. Add egg whites and sugar to the bowl and simmer over a pot of simmering water like a double boiler. Whisk constantly but gently until temperature reaches 160 degrees F. If you don't have a candy thermometer, simmer until the sugar has dissolved and the egg whites are hot.
Bring the bowl back to the stand mixer and with the whisk attachment, begin to whip the egg white mixture until the meringue is thick and glossy. Keep whipping until the bottom of the bowl is neutral to the touch and no longer warm. This takes at least 10-15 minutes.
On low speed, beat in the pieces of butter one piece at a time until incorporated. Keep mixing until the frosting is smooth. If mixture is too runny, pop in the fridge for about 15 minutes and whip again. If it looks curdled, keep on beating and it should eventually come back together. Keeping it on low speed, add vanilla, reduced champagne, and salt and mix until well incorporated. Tint with food coloring one drop at a time until it's the desired color.
To assemble the cake:
Use a long serrated kitchen knife or a wired cake splitter to split each cake layer into 2 horizontal layers.
Place the bottom of one of the split cake layers on a serving plate. Spread 1/3 of the strawberry mousse filling over the layer leaving about ½ inch border all around. Repeat with the second and third layers. Place the last cake layer on top.
Add a thin layer crumb coat of the buttercream to the cake and let set. I usually put it in the freezer for 10-15 minutes to set. This will help set the crumbs so you don't have crumbs mixed into the rest of the frosting. Finish frosting the cake using an offset spatula to spread the buttercream frosting over the top and sides of cake.
How to Make a White Chocolate Bow Cake Topper: To make the bow, I use melted white chocolate discs from a cake supply shop or the cake section of a craft store. The discs come in several different colors including pink. I learned this bow making technique many years in a cake decorating class. I also like it because it's not fondant. Fondant is fun and beautiful to decorate with, but I don't really like the taste of it. These white chocolate bows taste so much better than fondant! So here's how to make these bows:
Recipe source from http://www.lilikoijoy.com/2013/07/pink-champagne-cake.html