I wanted to find out if I could just throw two mashed bananas into a chocolate cake batter and expect that everything will just turn out fine. So I did! And the answer is…yes! But it might depend on the recipe. I would not conclude that this is true for any cake recipe. It seemed to be fine for the recipe I chose, which is the Chocolate Souffle Cake recipe from Tartine Bakery.
The next time, though, (if there is going to be a next time), I will blend the mash bananas more, and strain it to remove any lumps, because finding small lumps of soft cooked banana in the cake was not a good thing. Trust me, you might think finding lumps of banana would be pleasant enough to find in a cake, like I did. But it’s just not. Maybe if it was banana bread. Oh well, live and learn.
If you want a chocolate cake without the bananas, just leave it out, and it will be one of the best flourless chocolate cakes out there. It’s less dense than other flourless cake recipes, because the egg whites are whipped up and added separately, and right before baking, which lightens it up, I think.
The texture of the finished cake is better at room temperature, which is almost like a very smooth, silky mousse. It’s still good refrigerated, but it feels heavier and more firm. And since I did not include the chiffon cake base in the original, it is gluten-free. The original recipe from their cookbook calls for a 10-inch round springform pan, but I halved it to fit a 7-inch round springform pan, and since I added two bananas to the batter, it filled the pan completely to the rim and needed almost 10 extra minutes more than the original to bake completely. But I think it works well if you want a chocolate cake with a strong banana flavor. Enjoy!
2 medium-sized bananas, mashed, blended well and strained to remove lumps.
7 ounces dark bittersweet chocolate, chopped
3.25 ounces butter, unsalted
4 eggs, separated
3 ounces baker’s, or caster, sugar
1/8 tsp salt
for optional chocolate ganache topping for drizzling:
2 ounces bittersweet chocolate, chopped
1/3 cup + 2 Tablespoons heavy whipping cream
Preheat oven to 325 degrees F. Line bottom of pan with a parchment paper, cut to fit exactly at the bottom. Leave the bottom and sides ungreased. Mash bananas. For a smoother consistency, blend with blender to liquefy and put through a strainer to remove lumps. Set aside. In a small saucepan, melt the butter over medium heat, then add the chopped chocolate and stir to melt and blend into butter. Be careful not to get chocolate too hot. Fold into the bananas. Mix thoroughly until the whole mixture is one chocolate color, with no streaks of banana or butter. Set aside.
Separate eggs into whites in one bowl and yolks into another bowl. Add half the sugar (1.5 ounces) into the yolks and blend on medium with a hand-held mixer for about 4-5 minutes, or until the ribbon stage, which is when you lift the batter and let the batter drip back to the bowl and it looks sort of like a ribbon; it doesn’t disappear into the batter, but instead leaves traces on the surface that resemble a ribbon.
Clean the beater so that it is completely free of oil or debris. Make sure the beaters are dry and clean. Beat egg whites with the remaining half of the sugar, and add the salt. Beat until medium stiff peaks form. Fold a third of the egg whites into the chocolate mixture until no white streaks remain. Carefully fold in the rest of the egg whites.
Pour into prepared pan, and bake for about 45-50 minutes, or until top is no longer shiny, and toothpick test comes out clean. (If not using bananas in recipe, bake for about 35-40 minutes.) Let cool completely in the pan on a wire rack. Cover and refrigerate until well chilled, at least 3 hours, or up to overnight. To add chocolate ganache, heat whipping cream until almost boiling. Add to 2 ounces of chopped bittersweet chocolate and let sit for 2 minutes, then whisk until smooth, being careful not to overmix. Pour the ganache over the top of the cake, letting it drop down the sides, if desired.