Preheat oven to 350°F / 180°C (320°F / 160°C if using fan-assisted oven or convection oven).
Line the bottom of 9x13 cake pan with parchment paper.
Make the 9x13 vanilla cake
Dry ingredients – Sift the flour, baking powder, and salt into a medium bowl and mix them together using a whisk. Set aside
375 grams all-purpose flour
2 ½ teaspoon baking powder
½ teaspoon fine salt
Cream butter & sugar – In the bowl of a stand mixer fitted with the paddle attachment, beat the butter, sugar, and vanilla on medium speed until light and fluffy, about 8 minutes.
227 grams unsalted butter
300 grams white granulated sugar
1 teaspoon pure vanilla extract
Add the eggs – two at a time until each addition is incorporated before adding the next. It is always a good practice to scrape down the sides and bottom of the bowl with a spatula to ensure that all ingredients are combined well.
200 grams eggs (without shell)
Add wet and dry ingredients – Add the flour mixture you’ve made earlier in four parts, alternating with the milk in three parts. Beat just until each flour addition is incorporated before adding the next.
240 grams full fat milk
Pour into a lined 9×13 baking pan and smooth the surface using your spatula (an offset spatula is the best). Make it as flat and even as you can.
Bake for 40 minutes at 350°F / 180°C (320°F / 160°C if using fan-assisted oven or convection oven). The cake is ready when the top is a little golden brown (refer to photo) and when a toothpick inserted comes out clean or with few small crumbs.
Cool – Remove the cake from the oven and put over the cooling rack. When the cake has fully cooled down, refrigerate it (still in the pan) for about one hour.
Make the faux Swiss meringue buttercream
Dry Ingredients – In a bowl of a stand mixer fitted with whisk attachment, combine the pasteurized egg whites, powdered sugar, and salt. Mix everything together on low speed until well combined. Turn off the mixer off then scrape down the sides and bottom of the bowl. Set the mixer to medium high speed and continue to beat for another 5 minutes.
180 grams pasteurized egg whites
680 grams powdered sugar
1/2 teaspoon fine salt
Add butter and vanilla – Turn the speed to medium-low then start adding the butter in chunks, about 1-2 tablespoons at a time. When all the butter has been incorporated, add the vanilla extract. The buttercream will not look smooth YET at this stage.
680 grams unsalted butter
2 tablespoon pure vanilla extract
Whip the buttercream – Stop the mixer and scrape the sides and bottom of the bowl again. Set the mixer speed to medium and beat the mixture for another 10 to 12 minutes, until you have a smooth and creamy buttercream.
Add Color (optional) – If you are going to color your buttercream, add your drop(s) of food color then whip on high until the color is evenly incorporated.
Smoothen (optional) – Switch to paddle attachment and mix on low speed for 15-20 minutes. This will remove air bubbles and will make your buttercream really smooth. If you want a super creamy frosting, this is the trick!
Assemble the cake
Using the 4-inch cookie cutter, cut out 6 little cake circles from the 9×13 vanilla cake.
Level and torte each mini round cake. To torte means to divide the cake horizontally so we can get 2 layers per cake.
Put the layers on a parchment paper. Spread an even layer of buttercream on top of the cake layer with an offset spatula.
Stack the next cake layer on top and cover the cake with a thin layer of buttercream. Smooth the frosting using a bench scraper and/or small offset spatula.Chill the cake again in the fridge (20 minutes) or the freezer (10 minutes) until the buttercream is firm to the touch.
Cover the cake with a thicker layer of buttercream and smooth using a small offset spatula or a bench scraper.Chill the cake again in the fridge (20 minutes) or the freezer (10 minutes) until the buttercream is firm to touch. This will make it much easier to decorate the cake and move to its box.
Decorate as you like! Pipe some buttercream, use sprinkles, chocolate shavings, candies, or even fresh fruit to prettify you cake. Get creative and have fun!