Unroll the pastry into a 9-in. fluted tart pan with removable bottom.
Press onto bottom and up sides of pan; trim pastry even with edge (discard or save trimmed pastry for another use). Generously prick bottom of crust with a fork. Bake 9-11 minutes in a preheated 450-degree oven or until golden brown. Cool completely on a wire rack.
Reserve 2 Tbsp. Nutella for topping; spread remaining Nutella into cooled crust.
In a small saucepan, combine caramels and cream; cook over medium-low heat until blended, stirring occasionally. Remove from heat; stir in macadamia nuts. Spread evenly over Nutella.
In a microwave, heat reserved Nutella until warmed; drizzle over filling.
Refrigerate 1 hour or until firm. If desired, serve with whipped cream.
To toast nuts: spread in a 15x10x1-in. baking pan. Bake at 350 degrees for 5-10 minutes or until lightly browned, stirring occasionally. Or, spread in a dry nonstick skillet and heat over low heat until lightly browned, stirring occasionally.