Preheat the oven to 350 F. In a bowl, mix together the all-purpose flour, cinnamon, baking powder, baking soda, salt, and nutmeg. Set aside.
In another bowl, whisk together the eggs, vegetable oil, drained crushed pineapple, granulated sugar, light brown sugar, and vanilla extract until combined.
Add the dry ingredients to the wet. Stir just until combined.
Then, gently fold in the grated carrots, chopped walnuts, and pecans into the batter.
Grease and flour two 9-inch cake pans.
Pour half of the batter into each prepared cake pan. Bake for 40-50 minutes or until a toothpick inserted in the center comes out clean. Remove from the oven and let cool to room temperature.
While the cake layers are cooling, prepare the frosting. In a mixing bowl, beat together powdered sugar, cream cheese, butter, heavy cream, and vanilla extract until smooth and well combined.
spread frosting on top of one of the cakes. Place the second cake over the first one to make one big cake and frost the top and sides of this big cake. Sprinkle with additional chopped walnuts/pecans if desired. Slice and enjoy!