Preheat your oven to 350°F (175°C).

In a saucepan over medium heat, combine the milk and sugar; stir until warm and sugar dissolves.

Whisk egg yolks in a separate bowl; gradually add half of the warm milk mixture while whisking continuously. Return the mixture to the saucepan.

Cook over medium heat, stirring constantly until thickened (about 5 minutes). Remove from heat and stir in vanilla extract.

Pour half of the custard into the graham cracker crust, layer with sliced bananas, then top with remaining custard.

Refrigerate for at least 4 hours or overnight. Serve topped with freshly whipped cream.