Preheat oven to 350°. Stir together first 5 ingredients; spread in a thin layer on a baking sheet.
Bake at 350° for 15 minutes. Cool completely on a wire rack. Process in a food processor until finely chopped; set aside.
Stir together 2 cups brown sugar and next 3 ingredients in a large saucepan over low heat, and simmer, stirring often, 1 minute. (Do not boil.)
Beat egg yolks until thick and lemon-colored. Gradually stir 1 cup hot brown sugar mixture into yolks. Add egg yolk mixture to remaining hot mixture; cook, stirring constantly, over low heat 2 minutes or until mixture begins to thicken. Remove pan from heat; stir in cream, condensed milk, and vanilla. Let cool to room temperature.
Pour mixture into freezer container of a 6-quart hand-turned or electric freezer, and freeze according to manufacturer's instructions 5 to 7 minutes or until partially frozen. Layer top of ice cream evenly with oat mixture and caramel topping. Freeze according to manufacturer's instructions, 10 to 15 more minutes or until mixture is frozen. (If desired, remove mixture from freezer container, and place in another container. Return to freezer, and freeze 8 hours or overnight.)