Softened butter for greasing the baking pan (about 3 tbsp./42g)
2 cups all-purpose flour (250g)
1 tbsp. baking powder (12g)
½ tsp. baking soda (3g)
1 tsp. salt (4g)
½ tsp cinnamon (1g)
½ tsp nutmeg 1g)
½ cup buttermilk or sour cream (120g)
1 stick butter, softened (115g)
2 tbsp. vegetable oil (30ml)
1 cup brown sugar (125g)
½ cup sugar (62g)
1 ½ cups ripe mashed banana (Domenico bananas preferred) (337g)
½ cup milk (120ml)
½ cup walnuts, chopped (57g)
*About 8 mini-bananas (Domenico variety)
Powdered sugar for dusting
Berries and mint for garnish
Heat your oven to 350°F (176°C). Prepare a 12” round cake pan (30cm) or a 9″x 13″ baking pan (33cm x 23cm) by greasing generously with butter. For easier cake removal, line the bottom of the pan with parchment, but make sure to butter the parchment
*Optional fresh banana topping: Slice the Domenico bananas lengthwise using a mandoline slicer so that the slices are even. Line the prepared pan with the banana slices. Start with a pinwheel patter in the middle of the pan, and then work your way towards the outer edges of the pan. The rounded outside pieces of the banana may look better in the center pinwheel, using the larger slices towards the outside.
In a large bowl, sift together the flour, baking powder, baking soda, salt, cinnamon, and nutmeg. Set aside.
In a separate medium bowl, use a hand mixer to cream the buttermilk, butter, vegetable oil, brown sugar, sugar, and eggs. Beat for about 1 minute until well combined. Add the mashed banana and milk, continuing to beat for another minute.
Add the flour mixture by large spoonfuls, beating for about 30 seconds between each spoonful until all of the flour is incorporated. Stir in the walnuts using a rubber spatula, scraping down the sides of the bowl so that the batter is evenly combined.
Pour the batter into your prepared pan. Bake the cake in the heated oven for 35-45 minutes, until a toothpick comes out clean from the center. Remove the cake from the oven, allow to cool for about 5 minutes, and then invert the cake onto a wire cooling rack. Remove any parchment paper from the cake. Allow the cake to cool completely.
Dust the cooled cake generously with powdered sugar, and garnish with banana slices, berries, and mint.