Preheat oven to 350 degrees and grease a 9x13 baking dish with non-stick cooking spray
In a large mixing bowl, whisk together eggs, milk, sugar, and vanilla until fully combined
Stir in cubed bread, sliced bananas, and chocolate chips and allow the mixture to sit for 5 minutes so the bread begins to absorb the liquid
Pour mixture into prepared pan. Bake in preheated oven for 50 minutes until the custard has been absorbed and the top is golden brown