4 oz. Cream cheese, softened
3 Ripe bananas, mashed
1 Large egg yolk, divided
2 Large eggs
1 tsp. Pure vanilla extract
1/4 cup Buttermilk
3/4 cup Sugar, divided
1/4 tsp. Kosher salt
1 tsp. Baking soda
1 cup All-purpose flour, divided, plus more for pan
1/2 cup Melted butter, plus more butter for pan