Spray 2 (8-inch) round cake pans with baking spray. Line with parchment paper.
For the cake:
Beat the sugar, oil, and eggs together in the bowl of an electric mixer. Add the vanilla.
In a medium bowl mix together the flour, cinnamon, baking soda, and salt. Whisk well.
With the mixer on low-speed, gradually add the dry ingredients to the wet ingredients. By hand fold in the raisins, pineapple, coconut, and half of the pecans.
Gently fold in the carrots until well incorporated. Stir in a couple drops of purple food coloring if desired.
Divide the batter equally between the 2 prepared pans. Bake for 55 to 60 minutes, or until a toothpick inserted into the center comes out clean.
Remove the cakes from the oven and allow to cool completely, still in the pans on a wire rack.
For the cream cheese frosting:
Mix the cream cheese, butter and vanilla in the bowl of an electric mixer until just combined. Gradually add the confectioner's sugar and mix until creamy and smooth.
Remove the completely cooled cakes from the pans and peel the parchment paper off.
Place 1 layer with the flat side up, plate or cake pedestal. Place small stops of waxed paper under the edge to keep the plate clean.
Using an offset spatula, spread the top with frosting just to the edges. Place the second layer on top, flat side up.
Using a pastry bag filled with cream cheese frosting, fill in the space between the layers.
Ice the sides of the cake with frosting and pat finely chopped nuts on the sides.
Spread frosting on the top of the cake. Use a star tip to decorate the bottom and top edges.
For the buttercream frosting:
Place softened butter into the bowl of an electric mixer. Turn the mixer on a medium setting and cream the butter until it is smooth.
Add the confectioner's sugar, ½ cup at a time, turning the mixer onto the highest speed setting after each addition.
Add milk, heavy cream or half-and-half until the frosting has reached the preferred consistency. For a firmer frosting, add more confectioner's sugar, ¼ cup at a time.
For a softer frosting, add more milk or cream, a tablespoon at a time. Divide the frosting into two bowls, ⅔ in one bowl and the rest in the other. Using gel food coloring tint the larger amount of frosting purple and the other green.
Make carrot shapes from the purple and green buttercream icing using a round tip and a leaf tip. Practice on wax paper before trying this on your cake.
Serve cake at room temperature for best consistency.