For my husband’s grandma’s birthday I was asked to make a birthday cake for the family (~30 people). She is close to 100 years so I wanted to do something special. Her nickname is Anna banana, so I thought, why not a banana cake?
I had my doubts, “banana cake, kind of unusual for a birthday cake” and “will everyone like banana?” But it was well-received and my husband overheard someone say, “Ooh banana cake, I never had this before”. I even convinced myself, someone who only likes banana in banana form and banana bread form, to love this cake. The banana cake recipe is so good and great as a breakfast cake too.
I decided to do a chocolate ganache filling with this cake because banana and chocolate is a delicious combination! I added toasted hazelnuts in the center of the cake for some crunch since it was all soft ingredients. I knew I wanted the outside of the cake to be a Nutella frosting of some sort to please the crowds. Since I had a rich chocolate ganache filling decided to do a lighter buttercream, so my go to is a swiss meringue. Hope you like the combination! This goes on my make-again cake list!
Banana Cake with Chocolate Ganache Toasted Hazelnut Filling and Nutella Swiss Meringue Buttercream
Yield: two 9 inch cakes
For the Banana Cake
- 1 ½ cups bananas , mashed
- 2 teaspoons lemon juice
- 3 cups all-purpose flour
- 1 ½ teaspoons baking soda
- ¼ teaspoon salt
- generous pinch of freshly grated nutmeg
- ¾ cup unsalted butter , room temperature
- 2 1/8 cups sugar
- 3 large eggs, room temperature
- 2 teaspoons vanilla
- 1 ½ cups buttermilk, room temperature
For the Chocolate Ganache and Toasted Hazelnut Filling
- 2 cups (12 ounces) chocolate chips
- 1 cup heavy whipping cream
- 2 – 3 tablespoons vanilla extract
- 1 1/2 cups toasted hazelnuts, coarsely chopped
For the Nutella Swiss Meringue Buttercream
- 5 egg whites
- 1 and 1/2 cups sugar
- 1 and 1/2 cups unsalted butter, softened but still cool
- 2 teaspoons vanilla extract
- 1/4 teaspoon kosher salt
- 2/3 cup Nutella (or other chocolate/hazelnut spread)
For the Banana Cake
- Preheat oven to 275°. Grease and flour two 9 inch cake pans. You can also make this in a 9 x 13 inch pan.
- In a small bowl, mix mashed banana with the lemon juice; set aside. In a medium bowl, mix flour, baking soda , nutmeg and salt; set aside.
- In a large bowl, cream butter and sugar until light and fluffy, about 5-8 minutes. Beat in eggs, one at a time, then add in vanilla.
- On low, add the flour mixture alternately with the buttermilk. Stir in banana mixture.
- Pour batter into prepared pans and bake in preheated oven for one hour and 20 minutes or until toothpick inserted in center comes out clean. Unmold on to wire racks and cool completely.
For the Chocolate Ganache and Toasted Hazelnuts
- Heat heavy cream in a heavy pan on medium heat until it comes to a boil.
- Remove from heat and stir in chocolate chips until the mixture is smooth.
- Stir in optional flavoring.
- Let chocolate mixture cool in a refrigerator for 1 hour.
- When the mixture is at a “spoonable” consistency, place in mixing bowl.
- Whip mixture with either the whisk or beater attachment of your mixer for 2 minutes until slightly whippy but not light
- Chop hazelnuts and toast on a pan stirring frequently until nutty smell emerges.
For the Nutella Swiss Meringue Buttercream
- Bring a small amount of water to a rolling boil on the stove top in a large saucepan that allows the bowl of your stand mixer to sit atop the saucepan without touching the boiling water. Whisk together egg whites and sugar in the bowl of your stand mixer. Place over rolling water (similar to a double boiler) and whisk constantly until the sugar is dissolved and no longer grainy (rub the mixture between your fingers to test). Once the sugar has dissolved, immediately transfer bowl to stand mixer and whisk on medium high speed until the eggs form stiff peaks AND the bowl is cooled to room temperature. Switch to the paddle attachment and add butter 2 pieces at a time until incorporated. Continue to beat the mixture until it forms a smooth, silky frosting. If the mixture is runny or begins to curdle, do not fear – just keep beating until it comes together. This can take up to 10-15 minutes.
- Once the mixture comes together, add the salt and vanilla extract and beat to combine. Remove the bowl, and use a large spatula to carefully fold the Nutella into the frosting. Do NOT over mix – carefully fold the mixture just a few times to swirl the Nutella into the butter cream. You want to see streaks.
For the Assembly
- Split each 9 inch cake into two layers for a total of four layers.
- 1st Layer: spread 1/2 ganache and top with half of the toasted chopped hazelnuts
- 2nd Layer: spread nutella buttercream
- 3rd Layer: spread other half of the ganache and top with second half of the toasted chopped hazelnuts
- 4th Layer: frost cake with nutella buttercream
The main star ingredients!
And LOTS AND LOTS of BUTTER AND SUGAR.
Then adding in all the other ingredients, I almost overfilled my Kitchenaid! Never would’ve thought this would happen. Great motor on that thing, it did not die on me!
I multiplied the recipe a little too much and had two 8 inch cakes leftover…whoops…or was it a mistake? Anyway, time for the ganache. Make this ahead if you want since it needs time to chill. Mmmmm hot cream on the chocolate chips.
Time for the Nutella buttercream! You’ve all seen swiss meringue partly beaten, now here’s the fun part to swirl in the Nutella.
Now for assembly. Take the first layer and spread the chocolate ganache on top.
Then put the last layer on top and frost. For me, I did a crumb coat and then put my tiers on top of each other (big mistake, will explain later). I use bubble tea straws, I learned this trick from a cake decorating class. It’s strong enough to support the tiers and easy enough to cut with scissors.
I put the top tier on top and then measured the dowel rod to go down the entire cake to keep the tiers together. Don’t forget to cut a hole in the cardboard cake platter so the dowel can go all the way through. Here’s my crumb coated cake.
My icing bag “farted” during a rose piping, and messed it up. I just wiped it off and did a new one.
Just like that. To contrast the roses, I did a rustic horizontal top tier. I started by piping using a flat tip.
The final product!
And how did I screw up? In the transport of this cake. It was in the car, we drove for 1.5 hours, it was the last 5 minutes before arriving and…THE TOP TIER BROKE OFF!!!!! The bottom cake just broke to the weight of the top tier and car vibrations and the dowel rod ripped right through the cakes. Luckily it was all covered so the cake was still edible. But the presentation and aesthetics were little to be desired.