PREHEAT oven to 350° F.
COMBINE 1 1/2 cups mixed nuts, almonds and sugar in 5-cup blender container or food processor bowl fitted with metal blade. Cover; blend at high speed until finely ground. (Do not grind into paste.) Stir together butter and vanilla extract in medium bowl until well mixed. Add ground nut mixture; stir just until dough holds together. Press onto bottom of ungreased 9-inch tart pan with removable bottom. Place on baking sheet.
BAKE for 20 to 25 minutes or until golden brown. Cool completely in pan on wire rack.
COMBINE caramels and half-and-half in 2-quart saucepan. Cook over low heat for 15 to 20 minutes, stirring occasionally, until caramels are melted and mixture is smooth. Remove from heat; gently stir 1 1/2 cups mixed nuts and brandy extract into caramel mixture. Spoon onto cooled crust; spread to coat evenly. Cool for 30 minutes.
MELT morsels and vegetable oil in 1-quart saucepan over low heat until melted and smooth. Drizzle over tart. Serve with whipped cream.