Shortbread Crust

1. Pulse the flour, powdered sugar, and salt together in a food processor. Add the cold cubed butter and pulse until the mixture resembles coarse sand with some pea-sized pieces remaining.
2. Add cold water one teaspoon at a time, pulsing, until the dough just comes together when pressed. Do not overwork it.
3. Press the dough evenly into the bottom and up the sides of an 8-inch tart pan with a removable bottom. Prick the base all over with a fork and refrigerate for 30 minutes.
4. Preheat the oven to 350°F (175°C). Bake the chilled crust for 18–22 minutes until pale golden. Cool completely on a wire rack before filling.

Pastry Cream

1. Add the milk and vanilla bean (seeds and pod) to a medium saucepan and heat over moderate heat to scalding point (just before boiling).
2. In a medium heatproof bowl, whisk together the egg yolks and sugar. Whisk in the flour and cornstarch until you have a smooth, thick paste.
3. Remove the milk from heat and discard the vanilla pod. Slowly pour the hot milk into the egg mixture, whisking constantly to temper the eggs. (Strain through a sieve if any bits of cooked egg appear.)
4. Pour the mixture back into the saucepan and cook over medium heat, whisking constantly, until boiling and very thick, about 5 minutes. Boil for another 30–60 seconds to cook out the cornstarch. (The mixture will be very thick — add an extra splash of milk if needed to thin slightly.)
5. Pour into a clean bowl and press plastic wrap directly onto the surface to prevent a skin. Cool to room temperature, then refrigerate until needed. Give it a brisk whisk before using.

Whipped Cream

1. Beat the cream, icing sugar, and vanilla extract together until soft peaks form — you want it softly billowing, not stiff.

Assemble

1. Spread the pastry cream evenly over the cooled crust. Top with sliced bananas (a light spritz of lemon juice keeps them from browning).
2. Spread the whipped cream over the bananas. Scatter crushed confectionery, shaved chocolate, or more banana slices on top.
3. Refrigerate for at least 2 hours to chill before serving.