Combine vegetable oil, brown sugar and sugar in a mixer bowl. Add eggs and mix until combined.
Combine flour, salt, baking soda, cinnamon and nutmeg in a small bowl.
Alternate adding flour mixture and buttermilk to the mixer bowl until all combined.
Stir in vanilla, flaked coconut and chopped pecans.
Grease pans with non-stick cooking spray (or shortening). You can make in the 4 layer pan or 2 9-inch round pans. Pour batter evenly into each pan. Bake for 25 minutes.
Cool cake in pans for 10 minutes. Remove cake from pan and cool completely on wire racks.
To make the frosting, combine cream cheese and butter, beating until light and fluffy. Add powdered sugar and mix until smooth.
Stir in pecans.
Spread cream cheese frosting between layers and on top and sides of cake. Sprinkle top with toasted coconut and chopped pecans.
Notes
If you like a lot of frosting between layers, I would suggest doubling the frosting recipe.