Carrot Cake Cheesecake

Preheat oven to 350 degrees F and grease a 9" springform pan. Make carrot cake mixture: In a large bowl, combine flour, sugar, cinnamon, salt, and baking soda. Stir in oil, then add eggs and mix until combined. Add carrots, raisins, and nuts and mix until combined. Make cheesecake mixture: In a stand mixer fitted with the paddle attachment or in a large bowl with hand mixer, beat cream cheese and sugar until smooth. Stir in salt and flour. Mix in vanilla and eggs, beating 1 minute between each addition, then add sour cream. Assemble cheesecake: Pour 2/3 carrot cake mixture into prepared pan and smooth top with spatula. Top with spoonfuls of 1/3 cheesecake mixture, then pour over remaining carrot cake mixture. Top with remaining cheesecake mixture and smooth top with a spatula. Bake until center is only slightly jiggly, 1 hour. Let cool completely, 1 hour, then transfer to the fridge to cool at least 4 hours and preferably overnight. When ready to serve, make icing: Beat powdered sugar, butter cream cheese, and vanilla until smooth. Frost cheesecake, then garnish with pecans or walnuts and chill 10 minutes before serving.