Preheat your oven to 350°F (175°C). Grease and flour a 9×13 inch baking dish.
Cream together 1/2 cup of softened butter and 1 cup of sugar until light and fluffy.
Beat in the eggs, one at a time, then stir in the mashed bananas and 1 teaspoon of vanilla extract.
Whisk together the flour, baking soda, and salt in another bowl. Gradually add to the banana mixture, alternating with 1/2 cup buttermilk, beginning and ending with the flour.
Pour the batter into the prepared baking dish and smooth the top.
Bake for about 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Prepare the buttercream by creaming together 1/2 cup of softened butter, powdered sugar, 1 teaspoon of vanilla, cinnamon, and nutmeg until smooth.
Once the cake has cooled, frost it with the spiced vanilla buttercream.
Slice and serve your delicious banana cake!
Notes
Ensure all ingredients are certified gluten-free to avoid cross-contamination.