In a small bowl, whisk together flour, baking soda, cinnamon, and pumpkin pie spice.
In a large mixing bowl, beat eggs, pumpkin, granulated sugar, brown sugar, oil, pineapple, and buttermilk until combined.
Add the flour mixture to the mixing bowl, and beat until just combined.
Fold in carrots, coconut, raisins, and walnuts, stirring until just combined.
Divide batter evenly between two greased 9-inch round cake pans.
Bake at 350 degrees for about 35 minutes, or until edges are golden, and a toothpick inserted near the center comes out clean.
Cool in pans for 20 minutes, then remove to wire racks to cool completely.
Meanwhile, prepare cream cheese frosting.