In a small bowl, whisk together 1/4 cup of the milk with the cornstarch. Set aside.

In a medium saucepan, whisk together the remaining milk, salt and sugar. Allow mixture to heat over medium heat until it is just steaming; don’t let it boil.

Whisk the egg yolks in a separate bowl. While whisking, slowly stream the 1/2 cup of the hot milk mixture into the egg yolks. Slowly add the egg yolk mixture back to the pot, followed by the cornstarch mixture. Continue to cook over medium heat, whisking constantly, until the mixture starts to simmer and has thickened.

Remove from the heat and whisk in the butter and vanilla. Cool in a bowl covered with a layer of plastic wrap touching the top of the pudding to prevent a skin from forming.

To assemble: Place a tablespoon of cookie crumbs on the bottom of each serving dish. Layer slices of banana, pudding and then whipped cream. Repeat layers until you reach the top of the dish.