Preheat oven to 275 degrees F. (That is a correct temperature. This cake bakes at a low temperature.) Prepare a springform pan by lightly greasing it and lining the bottom with parchment paper.

Mash bananas and combine them with vinegar in a small bowl. Set aside.

Cream butter and sugar in the bowl of a large mixer. You should have a pale-colored mixture after about 2 minutes of mixing. Add egg and vanilla extract to the butter mixture. Mix to combine. Add half the flour, the baking soda and salt to the mixture and stir to combine. Mix in half the milk. Repeat with remaining flour, baking soda, salt and milk. Mix the ingredients to combine but be careful not to overmix.Fold in the banana mixture and pour the batter into your prepared springform pan.

Bake the cake in a preheated 275 degree F. oven for about 1 hour. Your cake is done when a toothpick inserted in the center of the cake comes out clean. Allow the cake to cool completely before frosting.

To make the whipped cream frosting, combine the whipping cream and powdered sugar and whip until soft peaks form. Add the peanut butter and mix just to combine. (Cook's Note: The first time I made this recipe the peanut butter made the frosting curdle. It tasted fine but was subpar visually. So, in subsequent bakes, I whipped the cream and the powdered sugar separately and then carefully and slowly added peanut butter to taste. That worked fine. To be fair, I'm working with a peanut butter that is not a name brand. It was the only creamy peanut butter I could find at the beginning of the lockdown.)