150grams2/3 cup unsalted butter, at room temperature
150grams2/3 cup caster sugar
1/2teaspoonvanilla extract
3Oreos, cream removed and crushed crushed to smithereens (and an additional 3-5 pieces roughly crushed for texture if desired)
Assembly
1Chocolate Genoise
1Simple Sugar Syrup
1Cream Cheese Buttercream or Tasty Kitchen's Best Frosting
10Oreos, cream removed and crushed (you can leave some big chunks for texture)
INSTRUCTIONS
Simple Sugar Syrup
Place the sugar and water in a small pot. Bring the mixture to a boil, swirling the pot to dissolve the sugar crystals. Boil for 2 – 3 minutes on high heat then remove the pot from heat. Let cool to room temperature before using.
Chocolate Genoise
Preheat the oven to 170 degrees Celsius. Grease a 7-inch baking tin and line the bottom with parchment paper. Set aside.
Sift the flour and cocoa powder together thrice. Set aside.
Place the eggs in a medium pot or a large metal mixing bowl. Add in the sugar and whisk immediately until combined. You must whisk the sugar immediately into the eggs otherwise lumps will form and it will be very hard to get rid of them later on.
Hold the pot / mixing bowl over medium-low heat and whisk the egg-sugar mixture constantly, to bring up the temperature until its like baby's milk - warm but not hot. The mixture would be foamy. You can set it directly over the heat, just make sure that you remove it from time to time so you don't end up with cooked eggs.
Transfer the mixture in the pot into a mixing bowl and whisk it with a hand-held electric mixer on high speed until the bubbles start to disappear. The mixture will triple in volume. Turn the mixer down to low and whisk it for at least 1 minute, to stabilize the air bubbles in the cake batter. The cake batter will leave a trail when you lift up the beaters and will sink and merge back slowly into the batter.
Sift in half of the flour mixture and gently fold it in until almost all are combined. Sift in the remaining half of the flour mixture and fold until no flour pockets are visible. Do not over-mix.
Add one-third of the cake batter into the hot, melted butter. Use a smaller spatula and fold the butter into the cake batter thoroughly. Pour the butter-mixed batter back into the rest of the cake batter and fold in gently.
Transfer the cake batter into the baking tin. Tilt the tin so the batter spreads out evenly and drop it several times on the counter top to burst the uneven air bubbles.
Bake in the middle rack for 15 to 20 minutes until the cake springs back when touched gently and a skewer inserted into the centre of the cake comes out clean.
Make ahead:Make the cake one day ahead and store in an air-tight container in a cool place or in the refrigerator.
Easy Chocolate Mousse
Melt the chocolate and let it cool to lukewarm. Whip the cream to soft peaks formed and fold in the melted chocolate.
Refrigerate the mousse for 10 to 15 minutes until it has thickened but still soft enough to be spread on the cake. If it has hardened, leave it out at room temperature to soften before spreading it on the cake.
Buttercream #1: Cream Cheese Buttercream
Using an electric mixer or food processor, beat the cream cheese, unsalted butter and icing sugar together until light and fluffy. Beat in the vanilla extract.
Remove a quarter of the buttercream and mix into the crushed Oreos. This would be your filling for the cake later on.
Remove half of the remaining buttercream and transfer it to a piping bag fitted with a star tip to pipe rosettes later on.
The rest of the buttercream would be used to frost the cake.
Buttercream #2: Tasty Kitchen's Best Frosting
Pour the milk into a small pot. Whisk in the flour with a wire whisk. Heat the mixture over medium-low heat and whisk constantly, until the mixture has thickened and has the consistency of a brownie mix (it should be very thick, like glue). Remove from heat and let it cool to room temperature completely.
In a clean mixing bowl, use an electric mixer and whip the softened butter and the sugar until the sugar has been fully incorporated (no graininess remains). Beat in the vanilla extract.
Scrape the cooled milk-flour mixture into the butter-sugar mixture and whip with the electric mixer until they have all combined together and resembles whipped cream.
Remove a quarter of the buttercream and mix it with the crushed Oreos. This would be your filling for the cake later on.
Remove half of the remaining buttercream and transfer it to a piping bag fitted with a star tip to pipe rosettes later on.
The rest of the buttercream would be used to frost the cake.
Assembly
Slice the genoise half vertically to get 2 7x3.5-inch rectangles. Slice each half horizontally to get 4 slices of genoise 7x3.5-inch each.
Place one layer of the genoise on a cake board. Brush with a layer of syrup - don't soak the cake!
Spread half of the chocolate mousse on top of the cake later, leaving a 1/4-inch border all around.
Brush the second layer of genoise with syrup on both sides then place it on top of the mousse.
Spread the Oreos-mixed filling onto the genoise, leaving a 1/4-inch border all around.
Brush the third layer of genoise both sides with syrup and place it on top of the Oreos filling.
Spread or pipe the remaining chocolate mousse on the genoise. Brush the last layer of genoise both sides with syrup and place it on top.
Spread a layer of frosting on the sides of the cake and a thinner layer of frosting on top.
Hold the cake (with the cake board) in your hand, press the crushed Oreos all over the sides of the cake. If desired, press some of the crushed Oreos on the top of the cake to create a border.
Pipe rosettes on top of the cake as close to each other as possible and refrigerate till ready to serve.