This cake hurts my feelings. I am upset that I have created this cake.
This cake just shut the whole game down. Switch off the internet. Unplug the blog. It's all over now.
You know me by now, which means you know there is going to be some slightly (or not slightly) annoying/time consuming procedure that makes this chocolate frosting and this banana cake the best thing in the world and you're not wrong, genius reader. You're not wrong.
But, my darling reader, you will be richly rewarded for your labor. Yes it takes an entire day to make this frosting, but look at how much hot fudge this recipe makes. LOOK.
You won't need all of it for the buttercream, so you can just jar the rest and keep it in the fridge, or give it to your friends if you hate personally enjoying hot fudge.
You have not had this hot fudge buttercream before, because I made it up. You have never had chocolate buttercream like this before. It tastes distinctly different from chocolate buttercream made with just cocoa powder or melted chocolate or both--it has a slight caramelized flavor to it from the hot chocolate (which cooks for upwards of 45 minutes). Its texture is richer than rich, smooth as silk and downright fatty. It's got this body to it, the kind of body you dream about: thick.
So first we're going to make this vat of hot fudge. Then you're going to let it cool completely (preferably overnight) and then we'll add it to some whipped butter to make the buttercream.
Now, look at my hot fudge recipe. Guess who is the star of the show? AGAIN?? That's right brilliant reader, my favorite baby, heavy cream. Heavy cream. As with caramel, any recipe for hot fudge that relies on evaporated milk is thumbs down into the center of the earth. It is just pure, rich cream that gives our hot fudge the fatty body it needs, no artificial thickeners or overly sweet cans of goo required.
Towards the end of the cooking process, the chocolate actually starts to separate, with visible chunks and an oily sheen in the mixture, and you will think it's all gone wrong. But this separation is exactly what we're going for, so don't worry. Once you whip in the butter the emulsion all comes together and you get that perfectly smooth, fatty mouthfeel only old-fashioned hot fudge sauce can provide. If you have an immersion blender, bust it out, as it is the ideal instrument for achieving the silkiest texture here.
It will go from upsetting liquids chocolate soup to a thicker glop then to oily mess then to PERFECTION.
This buttercream is not too sweet, so if you want it sweeter, feel free to add powdered sugar to your butter as you whip it up. Just a small amount, like a quarter cup, will add sweetness without adding grit.
HOT FUDGE SAUCE
3 c. heavy cream
1 3/4 c. (383 g.) granulated sugar
2 TBSP. corn syrup
4 oz. (115 g.) unsweetened chocolate, roughly chopped
1 1/2 tsp. kosher or sea salt
6 TBSP. unsalted butter, room temperature
1 tsp. vanilla extract
To make the buttercream you'll also need 2 cups (4 sticks) unsalted butter at room temperature and 1/4 c. powdered sugar (optional)
Stir together the cream, sugar, and corn syrup in a large heavy-bottomed saucepan over medium heat until the sugar is dissolved. Raise heat to medium high and bring to boil. Add the chopped chocolate and salt, stir. Reduce heat to low and simmer--you should have burbling in the center of the pot but not on the edges. Stir occasionally and let simmer for 45 to 50 minutes, until you see an oily sheen in the mixture and small solids separating out.
Turn off the heat and add the butter and vanilla, whisking vigorously or using your immersion blender. Let cool uncovered on the counter for at least thirty minutes, then cover with plastic wrap and transfer to the fridge to cool completely. Allow fudge to cool for at least four hours or overnight. Obviously, heat up your hot fudge sauce in the microwave (just a few seconds will do, be sure to stir well) before serving over ice cream or cake or just eating straight off the spoon.
TO make the buttercream, simply whip up your room temperature butter until light and fluffy, then add about half (two cups) of the cold hot fudge sauce. Add powdered sugar to taste if you like it sweeter.
Huh, I realize I took few photos of my banana cake, the actual...cake in this situation. Well, you can see where my priorities lie with this post and it is squarely with the hot fudge sauce. But I guess you do need some kind of cake to help chauffeur this buttercream to your mouth (or DO YOU??) so here's the banana cake part.
You'll need three very ripe bananas, not just spotty but very, upsettingly ripe. They should seem downright rotten. Allllll of the starch in these naners should be converted to sugar and their flavor should be super intense at this point. If you use only slightly overripe bananas you will end up with a drier, starchier cake with less flavor.
A little bit of brown sugar is a nice pairing with banana flavor, as is the tenderness that acidic heavy cream and vinegar brings. You could definitely use buttermilk here if you wanted to, but actually I was looking to avoid that unique buttermilk flavor in this cake to allow the banana to shine, but feel free to make the swap. This cake is quite sweet in my opinion, so it goes well with a rich, not-too-sweet frosting like this chocolate one, but a slightly tangy one is great too, like this cream cheese frosting.
I'm all for layering natural flavors with their extract versions, so if you have some banana extract there is nothing wrong with adding a small amount here to really deepen the banana flavor, but this cake is sufficiently banana-y enough without it.
2 c. (415 g.) granulated sugar
1/4 c. (45 g.) packed light or dark brown sugar
3 large, very ripe bananas
2 tsp. vanilla extract
1/4 tsp. banana extract
1 tsp. kosher or sea salt
3 large eggs, room temperature
1/2 c. heavy cream
1/2 tsp. apple cider vinegar
3/4 c. canola oil
2 2/3 c. (313 g.) cake flour (I use White Lily)
3/4 tsp. baking powder
3/4 tsp. baking soda
Preheat oven to 350 degrees F.
In a small bowl, whisk together the flour with the baking powder and baking soda and set aside. Add sugars, salt, and extracts to bananas in a large bowl and whip with a hand mixer until well incorporated and bananas are smooth. Add eggs and beat for two minutes until lightened. Add cream and vinegar and beat for one minute (this can be substituted for buttermilk if you prefer). Add oil and beat until incorporated. Finally, mix in 1/3 of the flour mixture on low until incorporated, then the rest of the flour; mix on low until batter is smooth.
Divide among three 8" or 9" pans, or spread into one 9x13" pan, and bake until center is just set, about 25-35 minutes. Cool completely, then frost.
It's a very light, tender and super moist cake, although very delicate and not easy to carve. I think the perfect thing to do with this guy is just throw it all in a 9x13 pan and frost when cool (some people call this "snack cake" but all cake is snack cake to me). It being January and our lives full of nighttime lately, I felt inspired to make a layer cake inspired by the night sky. I made a black dark chocolate ganache and some chocolate stars along with a big chocolate moon (which fell off the cake mid-shoot (you can see the crack in it where I repaired it in the candle photo). The night sky is wild and can't be held down, it reminded me.
For an extra sparkly nighttime, warm up your reserved hot fudge and serve it with the cake.