Gather the ingredients. Preheat the oven to 350 degrees F (175 degrees C). Grease and flour a 9x13-inch pan.

To make the cake: Mix flour, cinnamon, baking soda, baking powder, and salt in a large bowl. Make a well in the center and add sugar, oil, eggs, and vanilla. Mix with a wooden spoon until smooth. Stir in carrots, coconut, walnuts, and pineapple. Pour batter into the prepared pan.

Bake in the preheated oven until a toothpick inserted into the center comes out clean, about 45 minutes. Allow cake to cool completely before frosting. (The center of cake may sink slightly as it cools.)

To make the frosting: Beat cream cheese and butter in a mixing bowl until smooth. Add confectioners' sugar; beat until smooth and creamy. Spread frosting on top of cooled cake. Slice into squares and enjoy!