Preheat the oven to 350°F (175°C) and prepare a 9x5-inch loaf pan by greasing or lining it.

Mash 3-4 ripe bananas in a mixing bowl, then add granulated sugar, brown sugar, melted butter, eggs, and vanilla extract. Mix until creamy.

In another bowl, whisk together flour, baking soda, and salt. Gradually add to the banana mixture, folding gently until just combined.

In another bowl, beat softened cream cheese, powdered sugar, egg yolk, and lemon juice or zest until smooth.

Pour half of the banana batter into the prepared loaf pan, spread the cream cheese filling over, and top with the remaining banana batter.

Bake in the oven for 60 to 68 minutes, until the top is golden and a toothpick inserted comes out mostly clean.

Let the banana bread cool in the pan for about 10 minutes, then transfer it to a wire rack to cool completely.