Preheat the oven to 350 degrees F (175 degrees C). Grease and flour an 8x12-inch pan.
Sift flour, baking soda, cinnamon, and salt together in a medium bowl; set aside.
Mix sugar, eggs, buttermilk, oil, and vanilla together in a large bowl; gradually add flour mixture until just combined.
Combine shredded carrots, pineapple, coconut, walnuts, and raisins in a separate bowl; stir into cake batter using a large wooden spoon until combined. Pour batter into the prepared pan.
Bake in the preheated oven until a toothpick inserted into the center of the cake comes out clean, about 1 hour. Allow cake to cool for at least 20 minutes before serving.
