Heat oven to 350°F.
In food processor, process Crust ingredients except butter with on-and-off motions until fine crumbs form. Add 1/4 cup butter; process until well combined and a bit of the mixture pinched between fingers clumps together. Pour mixture into ungreased 9-inch glass pie plate; press in even layer in bottom and up side to form crust.
Bake in center of oven about 13 minutes. Remove from oven to cooling rack; cool completely, about 30 minutes.
Meanwhile, in 2-quart saucepan, combine 2 cups of the milk, 1/2 cup cream and 2 cups cereal. Heat to barely a simmer. Remove from heat. Cover; let stand 30 minutes to steep.
Strain cereal-milk mixture through fine strainer, pressing on cereal to extract as much liquid as possible. Discard cereal.
In small bowl, beat remaining 1/2 cup milk and the cornstarch with whisk until no lumps remain. Stir cornstarch mixture with whisk into cereal-milk mixture until combined. In another bowl (or the cornstarch bowl), beat egg yolks, 1/3 cup granulated sugar and 1/8 teaspoon salt with whisk until well combined and yolks begin to get pale and thick. Ladle a bit of the warm cereal-milk mixture into egg yolk mixture until combined. With rubber spatula, scrape egg yolk mixture into cereal-milk mixture in saucepan. Return saucepan to heat. Cook over medium-low heat, stirring constantly and making sure to scrape bottom and side of saucepan, until pudding thickens, whisk or spoon leaves tracks on surface of pudding, and mixture coats back of spoon.
Using immersion blender (preferred) or whisk, blend in 2 tablespoons butter. Cool pudding slightly.
Spoon or scrape half of pudding mixture into crust. Layer banana slices over first layer of pudding; top with remaining pudding, smoothing top. Place sheet of plastic wrap directly onto surface of pudding. Refrigerate pie until pudding is cool and set, about 2 hours.
Before serving, whip 1 cup cream and the powdered sugar with electric mixer on high speed until medium-soft peaks form. Spread over top of chilled pie.