1. Preheat oven to 350˚F. Coat a 10-cup bundt pan with nonstick cooking spray and set aside.
2. In a large mixing bowl, whisk together flour, baking soda, baking powder, salt, cinnamon, raisins and walnuts. Whisk together until evenly distributed and combined.
3. In another mixing bowl, whisk together eggs, olive oil, sugar, vanilla and carrots until smooth. 
4. Pour the wet mixture into dry flour mixture and fold together using a spatula until just combined and no dry ingredients are visible.
5. Pour the batter into the prepared bundt cake pan and bake for 60-65 minutes, or until a toothpick inserted into the center of the cake comes out clean.
6. Let the carrot cake cool for 10-15 minutes in the bundt pan on a wire cooling rack, then turn it upside down onto the wire cooling rack to remove. Allow the cake to cool completely before frosting.

For the cream cheese glaze:

1. In a medium mixing bowl, use a hand mixer to beat together cream cheese and butter until smooth and creamy. Add sugar and milk (1/2 tablespoon at a time) and beat until smooth and desired consistency is reached. The icing should be thin enough to pour but thick enough to coat the back of a spoon. If the icing is too thin, add in a little more sugar. If it is too thick, add in a little more milk. 
2. Use a spoon to slowly drizzle the cream cheese glaze over the cooled bundt cake and sprinkle chopped walnuts on top.