For the cake: Preheat the oven to 350℉. Spray Bundt pan with non-stick baking spray, set aside.
With an electric mixer beat the oil, sugar, and eggs. Add flour and cinnamon, mixing just until blended.
Stir in carrots and nuts.
Pour into prepared pan. Bang pan on countertop a time or two to remove any air bubbles. Bake in preheated oven for 50 minutes or until cake tests done with toothpick.
Remove from oven when done and cool in pan, on rack, for 10 minutes. Turn cake out onto cooking rack and cool completely.
For the frosting: Cream butter and cream cheese together using an electric mixer. Add powdered sugar and vanilla and blend. Mix in the pecans. Spread frosting on cooled cake.