For the prep:

Cup of Yum
1. Preheat oven to 350 degrees.
2. Spray a round 8-inch cake pan with baking spray then rub it with a small piece of paper towel to coat. Spray again lightly then line the pan with a circle of parchment paper. Set aside.
3. Line a sheet pan with foil. Set aside.
4. Mash 2 of the bananas on a plate with a fork until well fairly smooth. A few small lumps are fine. Measure out 1 cup. If you need more to equal 1 cup, use part or all of the 3rd banana. Set aside.

For the cake:

1. Add the soft butter to a medium-large mixing bowl. Stir until smooth. Add the granulated sugar and stir again (the mixture will be a little grainy at this point).
2. Add the egg and whisk vigorously for 30 seconds until nice and smooth.
3. Add the mashed bananas, buttermilk and the vanilla extract and whisk again for 30 seconds.
4. Add the baking soda, baking powder and salt and stir until everything is well incorporated.
5. Lastly, add the flour. Stir until the flour disappears. Make sure there’s no flour hiding at the bottom of the bowl but don’t over-mix at this point.
6. Transfer the batter to the prepared cake pan and spread to level. Set the pan on the prepared foil-lined sheet pan.
7. Bake for 30 minutes then pull up the foil around the edges of the pan to keep the sides of the cake from getting too brown. Cover the top of the cake lightly with a piece of foil.
8. Bake for another 10-20 minutes or until the top feels fairly firm when lightly touched for a total of 40-50 minutes. You can also insert a toothpick into the center of the cake. When it’s done, the toothpick will be clean when removed. The BEST way to determine doneness though is with an instant thermometer. Insert it in the center of the cake about halfway down. When the cake is perfectly done, it will read 200-205˚F (93-96˚C).
9. Allow the cake to cool in the pan for 10 minutes then invert onto a cooling rack. The bottom of the cake will now become the top. Allow the cake to cool for 45 minutes to an hour.

For the caramelized walnut topping:

1. Spray a spoon with nonstick cooking spray. Set aside.
2. Once the cake is cooled for at least 45 minutes, make the topping by melting the butter in a small sauce pan.
3. Add the brown sugar and whisk until nice and smooth. At first, the butter will seem separated. Keep whisking and it will come together.
4. Add the half and half and vanilla extract and whisk again. Bring the mixture to a boil and cook for 20 seconds without stirring.
5. Add the walnuts and stir to coat.
6. Turn off the heat but leave the pan on the burner. Spoon the hot mixture onto the cake with the prepared spoon. Spread to an even layer. Sprinkle with flaky sea salt, if desired. Allow to cool before serving. ENJOY!