Ferrero Rocher cake with hazelnut sponge layers, Nutella chocolate buttercream and crushed wafers. It tastes like one giant Ferrero Rocher.
- 7 large eggs room temperature
- ½ cup granulated sugar
- 2 cups hazelnut flour finely grated hazelnuts, 1 cup = 150 g, or almond flour (Note 1)
- 3 Tbsp all-purpose flour 1 cup = 150 g (Note 2)
- 3 Tbsp unsweetened cocoa powder
- 3 tsp baking powder (Note 3)
- 1⅓ cups unsalted butter room temperature (2⅔ sticks)
- 2¼ cups semi-sweet chocolate chips or a chopped bar
- ½ cup Nutella or any chocolate hazelnut spread
- 1½ cups hazelnut wafer cookies crushed
- 10 Ferrero Rocher candies for decorating
- ¾ cup hazelnuts chopped, for the sides (or more crushed wafers)
- 2 rolled wafer cookies optional, for decorating
-
Prep the pans. Heat the oven to 350°F (175°C). Line the bottoms of two 8-inch round cake pans with parchment rounds. Do not grease the sides - the sponge needs to grip them to rise.
-
Mix the dry ingredients. Sift 3 Tbsp all-purpose flour, 3 Tbsp unsweetened cocoa powder and 3 tsp baking powder through a fine-mesh sieve. Stir in 2 cups hazelnut flour (Note 1).
-
Whip the eggs. Fit a stand mixer with the whip attachment. Whip 7 large eggs on high until frothy, about 3 minutes. Slowly add ½ cup granulated sugar, then whip until pale, thick and tripled in volume, about 15 minutes. The batter should fall from the whip in a thick ribbon.
-
Fold gently. Fold the dry mix into the eggs in 3 additions with a wide spatula, just until no dry streaks remain. Do not overmix.
-
Pour the batter. Divide it evenly between the prepared pans, about 400 g each, and spread it to the edges.
-
Bake at 350°F (175°C). Bake both pans at the same time for about 45 minutes, OR until a toothpick in the center comes out clean (Note 4).
-
Cool. Cool in the pans for 5 minutes. Run a thin knife around the inside of each pan to loosen the cake, invert onto a cooling rack and peel off the parchment. Cool completely.
-
Melt the chocolate. Microwave 2¼ cups semi-sweet chocolate chips on low in short bursts, stirring between each. Stop when about ¾ has melted and stir until smooth. Cool to about 75°F (24°C), still fluid but cool on your lip.
-
Beat the buttercream. With the paddle attachment, beat 1⅓ cups unsalted butter, the cooled chocolate and ½ cup Nutella until smooth and fluffy (Note 5).
-
Split the layers. Cut each cooled cake in half horizontally with a cake slicer to make 4 layers.
-
Crush the wafers. Put 1½ cups hazelnut wafer cookies in a zip-top bag and roll over them with a rolling pin.
-
Save some buttercream. Set aside ¾ cup of the buttercream for the sides and top.
-
Anchor the first layer. Spread a dab of buttercream on the serving plate, set the first layer on top and press down.
-
Frost and sprinkle. Spread ¼ of the remaining buttercream over the layer and sprinkle with ⅓ of the crushed wafers. Repeat with the next 2 layers. Top with the last layer and the last ¼ of the buttercream.
-
Frost the sides. Cover the sides with the reserved buttercream using an offset spatula (a cake turntable helps) and press ¾ cup hazelnuts onto them, or use more crushed wafers.
-
Pipe and top. Pipe 8 stars on top with a piping bag and a 1M star tip, and set a Ferrero Rocher on each. Add the rolled wafers, if using.
-
Serve. Refrigerate if not serving right away, and bring to room temperature before slicing (Note 6).
1. Hazelnut flour: Use store-bought hazelnut flour (hazelnut meal), or make your own by grating whole hazelnuts on the fine drum of a rotary cheese grater. A food processor makes the nuts too coarse or oily, and the layers bake flat. For extra crunch, swap a little of the flour for pulsed hazelnuts. Almond flour works, with a milder flavor. All-purpose flour does not work in its place.
2. Measuring flour: 1 cup = 150 g. Weigh it if you can.
3. Baking powder when scaling: Changing the servings multiplies every amount straight across, but baking powder should not go up the whole way. For a double batch, use 5¼ tsp, not 6.
4. Bake both pans together: Batter that waits on the counter loses air and bakes flat. Check with a toothpick in the very middle, since an underbaked center sinks.
5. Buttercream: No powdered sugar needed. Too soft? Chill it for 15 to 20 minutes and whip again. If the butter melted from warm chocolate, start over with room-temperature butter and chocolate cooled to about 75°F (24°C).
6. Make ahead and storage: Bake the layers or make the buttercream a day ahead, or assemble the whole cake the day before. Keep the cake covered in the fridge for up to 3 days. Freeze the unfrosted layers, wrapped tightly, for up to 1 month, and thaw them in the fridge.
7. Pan sizes: For two 9-inch pans, set the servings to 15 (a quarter more of everything, but only 3½ tsp baking powder) and bake for the same time. For 10- to 11-inch pans, set the servings to 24 (use 5¼ tsp baking powder) and bake a little longer. Bake all the pans at the same time.
8. Eggs: Whole eggs, yolks and all. No cream of tartar needed.