Preheat oven 180 degree celsius. Coat the bundt cake with nonstick spray. Set aside.

In the bowl of your stand mixer fitted with the paddle attachment mix both sugars, vegetable oil, buttermilk, eggs and vanilla together on medium speed until smooth, 1 minute.

Add in the cinnamon, baking powder, baking soda, and salt and continue mixing for 30 seconds, scraping the sides of the bowl as necessary.

Mix in the flour until just combined. Add in the carrots, walnuts, and raisins and stir until evenly incorporated.

Pour batter into the prepared pan and bake for 40-45 minutes, or until a toothpick inserted int he center comes out clean.

Allow to cool completely.

To make Cream cheese icing: In the bowl of a stand mixer fitted with the paddle attachment (or in large bowl and using hand-held mixer) beat the butter on medium-high speed until creamy and lightened up, 1 to 2 minutes.

Add the confectioners sugar, salt and vanilla and beat until lightened in both color and texture and looks fluffier than when it started, 4 to 6 minutes. Beat in the sour cream.

With the mixer running on medium speed, add one piece of cream cheese at a time, one after the other, mixing well after each addition so there are no lumps. Continue adding the cream cheese until fully incorporated.

Increase the speed to medium high and beat until the frosting is light, fluffy, whipped-like and until almost no cream cheese lumps remain, 4 to 6 minutes. Use according to recipe above.