1. Preheat oven to 350oF.
2. Spray a 10-cup capacity bundt pan with baking spray.
3. Add cake mix, eggs, oil, water, sour cream, and vanilla to the bowl of an electric mixer.
4. Beat on medium speed for 5 minutes, scraping the bowl occasionally.
5. In a small bowl, toss apples with cinnamon. Set aside.
6. Remove bowl from mixer and add reserved apples and walnuts. Fold gently with a rubber spatula. Pour batter into prepared pan.
7. Bake for 1 hour to 1 hour 10 minutes or until a toothpick comes out clean. Let cool in pan for 10 minutes, then turn cake onto a wire rack to cool completely.
8. To make the caramel glaze, add brown sugar, butter, and cream to a medium saucepan.
9. Bring to a boil over medium heat, stirring often. Let boil for 1 minute without stirring.
10. Reduce heat to low and cook for an additional minute. Remove from heat and whisk in confectioners sugar and vanilla. Let stand to thicken, about 5 minutes.
11. Pour glaze over cake and sprinkle with sea salt.