⅓ cup plus ¼ cup unsalted butter, softened and divided
1 cup firmly packed light brown sugar
2 tbsp. dark rum
3 ripe bananas, halved crosswise and sliced lengthwise
¾ cup sugar
2 tbsp. vegetable oil
2 large eggs
2 cups all-purpose flour
2 tsp. baking powder
½ tsp. salt
½ tsp. cinnamon
¼ tsp. baking soda
¾ cup half and half
½ cup plain greek yogurt
½ cup mashed rip banana
1 tsp. vanilla extract
½ tsp. rum extract
Preheat oven to 350º. Spray a deep 10-inch cast iron skillet with baking spray with flour.
In the same skillet, melt ⅓ cup of butter over medium heat. Whisk in brown sugar and rum extract and cook; whisking constantly until sugar is dissolved, about 3 minutes. Remove from heat and let cool completely.
Arrange banana slices in overlapping concentric circles in the skillet with the sugar mixture.
In a large bowl, beat remaining ¼ cup butter, sugar and oil with a mixer a medium-high speed until light and fluffy, about 3 minutes. Stopping occasionally to scrape sides of the bowl. Add eggs, one at a time, beating well after each addition.
In a medium bowl, whisk together flour, baking powder, salt, cinnamon and baking soda. In a small bowl whisk together half and half, yogurt, mashed bananas and extracts. Add flour mixture to the butter mixture; alternating with half and half mixture. Beginning and ending with the flour mixture, beating just until combined after each addition. Gently spread batter onto the banana slices in the skillet.
Bake until a wooden toothpick inserted into the center comes out clean; 35-40 minutes. Let cool for 30 minutes. Run a knife around the sides of the skillet to loosen cake. Invert cake onto a serving platter and serve immediately. Cover and refrigerate for up to 3 days.