• Preheat the oven to 350 F and place a rack in the middle of the oven.

Banana Cake Batter

• In a medium sauce pan, add in the butter, place over medium heat and melt. Peel approximately 3 bananas (325 grams peeled) and cut in half lengthwise and crosswise. Pour in the brown sugar, cinnamon, and the bananas into the pan. Turn the heat down to low, cooking and stirring regularly until the bananas start to soften and become fragrant. It's ok if the bananas don't fully break down here.
• Once a bit soft and saucy, remove it from the heat and pour into a heat safe mixing bowl. Set aside to cool.
• If adding nuts, this is the perfect time to toast and chop them up. Use 150 -200 grams of walnuts or pecans.
• Once the banana mixture has cooled, pour in white sugar, salt, vanilla, sour cream, oil, espresso, and eggs. Whisk to combine - the whisking will break down the bananas. An electric mixer is great here but a regular manual whisk will work too just make sure everything is fully combined.
• In a separate bowl, whisk the flour and baking soda together.
• Pour the dry ingredients into the wet. Before mixing together, peel and chop the last banana into 1/2" chunks. Add the banana chunks (and nuts if adding) on top of the dry ingredients.
• Use a rubber spatula to fold the banana and dry ingredients into the wet ingredients. Mix until just combined.

Bake

• Line the 9"x9" pan with a baking spray including flour or parchment paper. Pour the batter into the pan. Then optionally sprinkle the top of the cake with an additional 50 grams of granulated sugar.
• Bake the cake on the middle rack in the preheated oven for 15 minutes. After 15 minutes rotate the pan 180 degrees and bake for another 10-15 minutes until the edges are golden brown and a toothpick inserted in the center comes out clean.
• Once baked, remove the pan from the oven and set aside to cool for 15 minutes before flipping out and leaving to cool completely.

Dark Chocolate Ganache

• In a medium heat safe bowl add in the dark chocolate. It should be roughly chopped or just broken up by hand.
• Heat the heavy cream in a microwave safe measuring cup on 30 second intervals until steaming or in a sauce pot on the stove.
• Pour the hot heavy cream over the chocolate and cover with a cutting board or lid. Let sit for 1 minute.
• After 1 minute has passed, remove the cover and whisk gently until smooth. Add in 40 grams of soft butter and whisk again until smooth.
• Set aside, stirring gently every 10-15 minutes until it has thickened and cooled enough to be spreadable but not run off the sides of the cake.
• Once thickened, scoop the chocolate ganache onto the cooled banana cake and use the back of a spoon or an offset spatula to smooth it out into a thick even layer on top of the cake.
• Sprinkle with flaky salt and set aside while making the whipped cream.

Sour Cream Whipped Cream

• This recipe makes a thick layer of whipped cream as is shown in the photo, if you prefer to make less you can always do half as much!
• In a small bowl, add in 50 grams of cold water and sprinkle the top with 1 packet (about 7 grams) of unflavored gelatin. Stir to combine and set aside.
• Pour the cold heavy cream into a large mixing bowl along with the powdered sugar, vanilla, and salt. Whip on medium speed until lines begin to form, you don't want stiff peaks yet.
• Microwave the bowl with the bloomed gelatin for 10-15 seconds until the gelatin has dissolved but it shouldn't boil!
• Let it cool for a couple of minutes.
• Return the mixer to medium high speed and slowly stream the gelatin into the cream. Whip until medium stiff peaks form, don't stop whipping and add in the sour cream.
• The gelatin will help it set so it doesn't need to be super stiff already from whipping, just firm enough to hold it's shape.
• Either pipe or plop the whipped cream, immediately as it will start to set, into a thick layer on top of the cooled salted ganache. Optionally dust with a bit of cocoa powder to serve.