Prep your pan: Use an 8- or 9-inch square dish, or a similar-size pie plate. Lightly grease the bottom if your dish isn’t nonstick.

Make the biscuit base: Crush the biscuits into fine crumbs using a food processor or a zip-top bag and rolling pin. Stir in the melted butter, sugar, and a pinch of salt until the mixture looks like damp sand.

Press and set: Firmly press the crumbs into an even layer in your dish. For a no-bake option, chill for at least 30 minutes. For a sturdier crust, bake at 350°F (175°C) for 8–10 minutes, then cool completely.

Whisk the dry custard mix: In a saucepan off the heat, whisk the sugar, cornstarch, and a pinch of salt. Add egg yolks and whisk to make a thick paste.

Temper with milk: Gradually whisk in the milk, a little at a time, until smooth with no lumps.

Cook the custard: Set the pan over medium heat, whisking constantly. Once it begins to bubble, keep whisking for 1–2 minutes until thick and glossy.

Finish the cream: Take off the heat. Whisk in butter and vanilla. For an extra-smooth finish, strain the custard through a fine sieve into a bowl.

Add banana flavor: Mash 2 ripe bananas until smooth. Fold the mash into the warm custard. Taste and adjust sweetness if needed.

Cool the filling: Press plastic wrap directly onto the surface to prevent a skin. Let it cool to room temperature, then chill until slightly cool but still spreadable, about 30–45 minutes.

Optional banana layer: Slice 1 banana. Toss slices lightly with lemon juice to slow browning. Arrange over the cooled crust.

Assemble: Spread the banana custard evenly over the crust (and banana slices, if using). Smooth the top. Chill for at least 2 hours, or until set.

Whip the cream: Just before serving, beat the cold heavy cream, powdered sugar, and vanilla to soft peaks. Don’t overwhip.

Top and garnish: Spread or pipe the whipped cream over the chilled banana layer. Finish with shaved chocolate, crushed biscuits, or a few fresh banana slices.

Serve: Slice with a sharp knife. Wipe the blade between cuts for clean layers.