Banana-Caramel Shortcakes

Heat oven to 425 ºF. You'll need a baking sheet. Stir sugar and water in a heavy 2-qt saucepan over medium heat until mixture comes to a boil. Boil 5 minutes, without stirring, scraping down sides of pan if mixture starts to crystallize around edges, or until mixture is caramel-colored. Whisk in butter until melted. Remove from heat and whisk in cream (mixture will bubble vigorously). Scrape into a medium bowl; cover loosely and refrigerate until cool. Whisk flour, walnuts, 2 Tbsp sugar, the baking powder and salt in a medium bowl until blended. Add cream; stir with a fork until mixture comes together to form a dough. Transfer dough to work surface and form into a 6-in.-long log. Cut into 6 rounds. Place rounds on ungreased baking sheet. Sprinkle tops with remaining sugar. Bake 14 to 17 minutes or until golden. Remove to wire rack to cool completely. Slice bananas and stir into caramel sauce. Beat cream, sugar and vanilla until soft peaks form when beaters are lifted. Halve shortcakes with a serrated knife. Place bottoms on dessert plates. Top each bottom with scant 1 ⁄4 cup banana-caramel mixture, then about 3 Tbsp whipped cream. Top with biscuit tops, 2 Tbsp banana-caramel mixture and 1 Tbsp whipped cream. Garnish. Plan ahead: Bake shortcakes no more than 8 hours before serving. When they're cool, store tightly covered at room temperature. Make the car