In a large mixing bowl, melt ½ cup unsalted butter and stir in 1 cup granulated sugar until well combined. Add 2 beaten eggs and 2 overripe mashed bananas, mixing until smooth. Gradually incorporate 1 ½ cups all-purpose flour, 1 teaspoon baking soda, and ½ cup chocolate chips, stirring just until combined.

In another bowl, beat 16 ounces of softened cream cheese until creamy. Gradually add ¾ cup granulated sugar, then mix in 2 eggs and 1 teaspoon vanilla extract until the batter is smooth.

Lightly grease a 9-inch springform pan. Layer spoonfuls of the banana bread batter and dollops of the cheesecake batter, creating a marbled effect.

Preheat your oven to 350°F (175°C). Place the springform pan inside a larger baking dish filled with hot water. Bake for 75-90 minutes until set.

Remove the cheesecake from the water bath and cool on a wire rack for about 1 hour. Then, refrigerate for at least 4 hours or overnight.

In a bowl, beat 8 ounces of softened cream cheese with ¼ cup unsalted butter until fluffy. Gradually mix in 1 ½ cups powdered sugar and 1 teaspoon vanilla until smooth, then spread over the cooled cheesecake.