Banana Pudding Layer Cake From Nola Restaurant

Name: Banana Pudding Layer Cake From Nola Restaurant
Cuisine: American
Ingredients: 1 cup graham cracker crumbs; 4 tablespoons melted unsalted butter; 1/4 cup light brown sugar; 1 very ripe banana, peeled and mashed, plus 8 or 9 firm, ripe bananas; 2 cups whole milk; 1 1/2 cups sugar; 1 vanilla bean; 5 large egg yolks; 1/4 cup cornstarch, sifted; 1 quart heavy cream; 1 ½ tablespoons gelatin (2 envelopes); 3 tablespoons cold water; One 12-ounce package vanilla wafers; Dried sweetened banana chips, garnish; Fudge sauce or chocolate sauce, accompaniment; Fresh mint sprigs, garnish