Foryoueats: Grandma's Carrot Cake

2 cups all-purpose flour

2 teaspoons baking soda

1 teaspoon ground cinnamon

2 cups white sugar

1 cup vegetable oil

3 eggs

1 teaspoon vanilla extract

2 cups carrots, grated

1 (15 ounce) can crushed pineapple, drained

1 cup chopped walnuts

1 cup flaked coconut

1 cup white sugar

½ cup unsalted butter

½ cup buttermilk

1 teaspoon vanilla extract

Grandma's Carrot Cake