To make the pudding, place the cornstarch in a heatproof bowl. Stir in 1/2 cup of the milk until evenly blended. Whisk in the egg yolks.
Combine the remaining 2 1/2 cups milk and 3/4 cup of the sugar in a heavy medium saucepan. With the tip of a knife, scrape the vanilla seeds into the pan; toss in the pod as well. Bring to a boil over medium heat; immediately reduce the heat to low.
Slowly whisk about half of the hot milk into the egg yolk mixture to warm it. Then whisk the hot egg mixture into the remaining milk in a slow, steady stream. Continue to cook, whisking, until the pudding comes to a gentle boil. Boil for a minute, remove the vanilla pod, remove from the heat, and scrape into a bowl. Press a sheet of plastic wrap directly onto the top of the pudding to prevent a skin from forming; refrigerate until cold, at least 4 hours or overnight.
To assemble the dessert, spread a thin layer of chilled pudding in a trifle dish or other deep glass or ceramic bowl. Top with a layer of overlapping banana slices and then a layer of ladyfingers. Cover with half of the remaining pudding, another layer of bananas, reserving a few slices for garnish, and then the rest of the ladyfingers, reserving 2 or 3 for garnish. Top with the remaining pudding. Cover with plastic wrap and refrigerate for at least 6 hours or up to a day in advance before serving so the cookies soften completely.
Shortly before serving, whip the cream and the remaining 1 tablespoon sugar in a chilled bowl with chilled beaters until soft peaks form. Top the banana pudding with dollops of whipped cream, a sprinkling of the reserved ladyfingers, crumbled, and a few slices of banana.
Excerpted from Desserts From the Famous Loveless Cafe by Alisa Huntsman (Artisan Books). Copyright 2011. Photographs by Karen Mordechai.