Ingredients Cinnamon Topping:1/3 cup brown sugar3 Tablespoons butter1 tablespoon cinnamonBanana Cake:2 bananas2 eggs1/2 cup brown sugar1/2 cup butter, melted1/4 cup sour cream, or Greek yogurt or milk1 teaspoon vanilla extract1 1/2 cups all-purpose flour1 teaspoon cinnamon1 tablespoon baking powderIcing:1 cup powdered sugar1 tablespoon milk or coffee1 teaspoon vanilla extractInstructions Preheat oven to 350° F. Prepare an 8×8 baking dish with parchment paper and set aside.In a small microwave-safe bowl, melt the butter. Add the sugar and cinnamon and stir to combine. Set aside.In a large bowl, mash the bananas, add the egg, sour cream, melted butter, sugar, and vanilla extract; whisk to combine. Add the flour, cinnamon, and baking powder and whisk for 1-2 minutes or until fully incorporated.Transfer the batter to the prepared baking dish and scoop the cinnamon mixture onto the cake batter. Use a fork to swirl the cinnamon mixture into the cake batter. Bake for 30 minutes or until cooked through.While the cake is baking, whisk the powdered sugar, milk, and vanilla in a small bowl. If the icing is too thick add another teaspoon of milk. Remove the cake from the oven and cool for 5-10 minutes then top with the icing.