Make the crust. In a bowl, mix graham cracker crumbs, sugar, and salt. Stir in melted butter until the mixture looks like damp sand. Press firmly into a 9-inch pie plate, going up the sides. Bake at 350°F (175°C) for 8–10 minutes until set and lightly golden. Cool completely. If using a pastry crust, blind-bake and cool.

Prep the bananas. Slice 1–2 bananas and toss lightly with lemon juice. Set aside for layering the bottom of the pie. Keep the rest for the top.

Whisk dry ingredients. In a medium saucepan (off heat), whisk sugar, cornstarch, and salt to break up lumps. This helps the custard cook smoothly.

Temper with milk and yolks. Add milk gradually, whisking until no dry spots remain. Whisk in egg yolks until fully combined.

Cook the custard. Set the saucepan over medium heat. Whisk constantly as the mixture warms, then thickens, 6–8 minutes. When it bubbles and holds lines from the whisk, cook 1 minute more to remove any starchy taste.

Finish with butter and vanilla. Remove from heat. Whisk in butter and vanilla until glossy. If you want a stronger banana flavor, swap half the vanilla for banana extract. For the silkiest texture, strain the custard through a fine-mesh sieve into a bowl.

Layer the pie. Arrange a single layer of banana slices on the cooled crust. Pour half the warm custard over them. Add another thin layer of banana slices, then the remaining custard. Smooth the top. Press plastic wrap directly on the surface to prevent a skin.

Chill to set. Refrigerate at least 4 hours, preferably overnight, until the custard is fully set and slices cleanly.

Whip the cream. In a chilled bowl, beat heavy cream, powdered sugar, and vanilla to soft peaks. Spread or pipe over the chilled pie. Top with fresh banana slices just before serving, plus toasted coconut or chocolate shavings if you like.

Slice and serve. Use a sharp, thin knife warmed under hot water and wiped dry for the cleanest slices. Enjoy cold.