Preheat the conventional oven to 350 degrees Fahrenheit. Then, take your 9-inch round cake pans. And grease them using vegetable shortening. After that, dust them with flour. Afterward, set it aside.
Next, separate the yolks from egg whites into different bowls and pour the buttermilk into a different mixing bowl. After that, add the baking soda and stir.
Afterward, cream the butter in a different mixing bowl. And beat it for about 2 minutes until the butter turns lighter in color. Then, add the white sugar. And mix it for another 2 to 3 minutes until it becomes light and fluffy.
Add the yolks to the mixture and then add the vanilla extract. Mix the mixture until everything combines well. Alternately add the flour with the mashed bananas. And mix with every addition.
Afterward, stir or mix the buttermilk with the baking soda in the mixture. Make sure to combine well.
With the use of an electric mixer, whisk the egg whites until it becomes stiff. Then, add the pecans into the cake batter mixture.
After that, take the cake batter and fold the egg whites using a rubber spatula. Then, pour the banana nut cake batter into the prepared cake pans.
Afterward, bake the banana nut cakes for 25 minutes. Or until the cake cooks thoroughly. To check if the cakes cook thoroughly, you can use a toothpick. With that, make sure to insert it at the center of the cake. If your toothpick comes out clean, it is okay. You can also use the pressing method. Press the cake; if it bounces back. And leaves no dent in the cake; it is ready.
Once the banana nut cakes cook entirely, take them out of the oven. And allow the cakes to cool over the counter for 10 minutes and turn over the cake into a cooling wire rack. And remove them from the round cake pans. Next, allow the cakes to cool completely and then set aside.