1 1/4cups(284g) unsalted butterat room temperature
1 tspvanilla pasteor vanilla extract
1/4tspkosher salt
Instructions
Strawberry Cake
Preheat the oven to 350℉ / 175℃. Generously grease three 8-inch / 20cm cake pans, then line them with greased parchment paper.
In a stand mixer fitted with the paddle attachment, cream the butter on medium-high speed until creamy and smooth, about 1 minute.
Turn the mixer speed to medium; add the sugar and vanilla to the butter and beat for about 5 minutes, until the mixture is light in color and about double in volume.
Turn the speed to medium-low, add the egg whites, a little at a time, about five equal additions, mixing each until completely incorporated before adding the next. Scrape the bowl after each addition. This takes some patience with this many eggs; don’t be tempted to add them too fast.
In a separate bowl, whisk together the flour, baking powder, and salt until well combined.
In a small cup stir together the strawberry puree and lemon juice.
Sift one-third of the flour mixture into the butter/egg white mixture and mix on low speed until combined. Scrape the bowl and add half of the strawberry puree and food color if using, mixing until combined. Repeat with another one-third flour, the remaining strawberry, and then the final one-third flour. Scrape down after each addition.
Pour the batter into the prepared pans and spread evenly using an offset spatula. Gently tap the pans on the counter several times to release excess air bubbles.
Bake until a tester comes out clean, 25 to 30 minutes. Allow to cool for 15 minutes in the pans, then remove from pans and transfer to a wire rack to cool completely. (The cake may shrink slightly in the pan as it cools, so don’t be alarmed.)
Whipped Cream and Berry Filling
In a stand mixer fitted with the whisk attachment, whip the heavy cream, confectioners' sugar, and vanilla on medium speed until it reaches medium-stiff peaks.
Wash the berries and dry on a towel. Cut half of the strawberries into 1/8-inch thick slices. Cut half of the remaining berries in half, leaving the greens on for decor (optional). Leave some berries whole for decorating.
Swiss Meringue Buttercream
In the bowl of a stand mixer fitted with the whisk attachment, combine the sugar and egg whites and beat on medium speed to mix. The mixture will be very thick and grainy.
Put 1 inch / 2.5cm of water in the bottom of a double boiler or a medium saucepan and bring to a gentle simmer over medium-low heat. Place the bowl with the sugar mixture over the simmering water and stir the mixture with a rubber spatula until the sugar is completely melted. Brush down the sides of the bowl with the spatula to make sure all the sugar is melted. Feel the mixture between your fingers to check for graininess. Once all the sugar has melted and the mixture is smooth, the syrup is hot enough (140°F / 60°C) to be safe to consume.
Return the bowl to the stand mixer fitted with a clean whisk attachment and beat on medium-high speed until the egg foam is light, fluffy, and glossy and the bowl feels just about room temperature. (If the egg foam isn’t cooled sufficiently, the butter will melt when you add it.)
Once the egg foam is whipped and cooled, turn the mixer speed to medium, add the butter, 2 Tbsp at a time, and beat until incorporated. Turn the speed to low, add the vanilla and salt, and mix until incorporated.
Use immediately.
Assembling the Cake
Place one of the cooled layers of cake on an 8-inch cardboard round and center in on a cake turner. Use a super slicer serrated knife to trim the cake of any crust (this step is optional).
Place 1/4 of the whipped cream over the cake layer, then add a layer of the 1/8-inch thick slices of strawberries and raspberries. cover with more cream.
Place a second layer of cake over the cream, repeat the trimming, if desired. Add more cream and this time scatter blueberries over the cream. Top with more cream and the last layer of cake.
Use the buttercream to crumb coat the cake and then do a final layer of buttercream. See my YouTube videos for these two steps.
Decorate with the remaining blueberries, raspberries and sliced & whole strawberries.
Serving suggestions
Serve the cake at room temperature. Buttercream is much better when room temperature. The cake may take a few hours to come to room temperature if it has been refrigerated.
Use a sharp knife dipped in hot water to slice the cake.
Notes
*To make strawberry puree: In a 2-cup measuring cup blend about 1/2 pound (227g) the strawberries until smooth. Set aside. You may have some extra puree that you can serve with the cake.