Ingredients

For the Chocolate Chip Cake:
• 5 egg whites, at room temperature
• 1 whole egg, at room temperature
• 1-1/3 (320 ml) cups buttermilk, at room temperature
• 2 teaspoons (10 ml) pure vanilla extract OR Princess Bakery Emulsion
• 2-3/4 cups (317 g) cake flour, sifted
• 1-3/4 cups (350 g) sugar
• 1 tablespoon + 1 teaspoon (18 g) baking powder
• 3/4 teaspoon (5 g) salt
• 10 tablespoons (130 g) unsalted butter, cold and cut into 20 even pieces
• 3/4 cup (130 g) quality semisweet chocolate chips
For the Peanut Butter Mousse:
• 1 package (250 g brick) cream cheese, cold and cut into cubes
• 1 cup (125 g) icing sugar (confectioners')
• 3/4 cup (130 g) smooth peanut butter
• 1 tablespoon (15 ml) pure vanilla extract
• 3/4 cup (180 ml) whipping cream (35% fat)
For the Vanilla Bean Whipped Cream Frosting:
• 2 cups (480 ml) whipping cream (35% fat)
• 1/4 cup (30 g) icing sugar (confectioners')
• 2 teaspoons (10 ml) vanilla bean paste
• Pinch of salt
For the Peanut Sugar Coating:
• 1/2 cup (75 g) roasted peanuts, chopped into small pieces
• 1/2 cup (100 g) turbinado sugar
• Few tablespoons of pink sanding sugar, optional
• 1 maraschino cherry

Instructions

For the Chocolate Chip Cake:
1. Preheat the oven to 350° F. Butter the bottom of three 7-inch round cake pans (or two 8-inch round or 9-inch round pans) and line bottoms with parchment rounds.
2. In a medium measuring cup with a spout, lightly whisk the egg whites and yolk. In a separate measuring cup, combine the buttermilk and vanilla.
3. In the bowl of an electric mixer fitted with the paddle attachment, whisk together the flour, sugar, baking powder and salt. With the mixer set to low speed, add the cold butter one piece at a time, about 10 seconds apart. (You can keep half in the fridge while you add the first half of butter.) Continue mixing on low speed until all of the butter has been blended and there are no clumps. Mixture should have a fine crumbly, cornmeal-like texture.
4. Gradually add the buttermilk mixture to these dry ingredients, and mix on medium speed for 4 minutes. Scrape the sides and bottom of the bowl to ensure all of the ingredients are well incorporated. Reduce the speed to low and gradually add the egg mixture; once the mixture has been added, increase speed to medium and beat for 1 minute, but no more.
5. Toss the chocolate chips with a few pinches of cake flour and gently fold into batter.
6. Divide batter evenly among the 3 prepared pans (use a kitchen scale to ensure 3 even layers--cakes should weight ~450 g each). Place two of the cake pans on a baking sheet and bake until a cake tester or wooden toothpick inserted into the center comes out with a few crumbs but no batter, about 23 minutes. Repeat with the final layer. Let the layers cool in the pans for 10 minutes, then loosen sides with thin metal spatula or knife, and carefully turn out onto wire racks, peel of the paper liners, and let cool completely.
For the Peanut Butter Mousse:
7. In the bowl of an electric mixer fitted with the whisk attachment, mix the cream cheese, icing sugar, peanut butter and vanilla on medium speed until smooth and fluffy, about 3 minutes. Transfer mixture to another bowl (unless you're lucky enough to have another mixer bowl). Wash and dry both bowl and whisk attachment and chill in the freezer or refrigerator.
8. Fit the mixer with the chilled bowl and whisk and whip the cream on medium high speed until firm peaks form (but not clumpy), about 1 minute. Fold whipped cream into peanut butter mixture and cover and chill until ready to use.
For the Vanilla Bean Whipped Cream Frosting:
9. Chill your mixer bowl and whisk in freezer for 5 minutes, then whip the cream, icing sugar and salt on medium high speed until firm peaks form (but not clumpy). Add vanilla bean paste and mix on low speed until incorporated. Best used right away.
Assembly of the Cake:
10. I recommend making the filling while the cakes are in the oven, and then chilling until the cakes are cool. Once cakes are cool and you have filled them with the peanut butter filling, make the whipped cream frosting (it only takes a couple of minutes to make).
11. Trim any dark edges or crust from cake layers with a very sharp serrated knife. Place your first cake layer, face-up, onto a cake stand, plate or cake board. Place half of the peanut butter filling on top of the layer and spread evenly using a small offset spatula.
12. Repeat until you come to your final cake layer, which you will place face-down. If you find the cake too soft and unstable, put in refrigerator for a few moments to firm it up, then resume. Use your clean offset spatula to carefully smooth the frosting so it's flat against the cake.
13. an even layer of frosting to the entire cake, to seal in crumbs. Chill again until frosting is firm, about 30 minutes.
14. Place cake plate/board with cake onto a turntable, if possible. Using an offset spatula, spread the whipped cream frosting on the top of the cake, letting it extend about 1/2" over the edge, then smooth excess onto side of cake. With a medium straight spatula, cover the sides of the cake until you have a smooth even coat of frosting by slowly turning the cake turntable with one hand while holding the spatula steady with the other. Use your small offset spatula to smooth top of cake. Place remaining whipped cream in a pastry bag fitted with an open star tip (I used #887) and pipe a border around the top perimeter for the cake. Chill for 30 minutes.
15. In a medium ziploc bag, combine the peanuts and sugar. Remove cake from fridge put back onto turntable. Place turntable and cake onto a baking sheet (for ease of clean-up), and gently coat the sides of the cake with the sugar mixture. (You may have to "throw" it at the cake!) Top with a maraschino cherry.
16. Keep cake refrigerated for up to 2 days, but serve at room temperature. Best enjoyed day 1.