A recipe for orange slice cake on About.com uses buttermilk, dates and orange slice candies. Prepare this dense cake at least one day before serving because the orange glaze needs time to soak.
Preheat the oven to 250 F, and prepare a 10-inch tube pan by lightly coating the inside with butter and flour. Cream 1 cup of room temperature butter or margarine with 2 cups of sugar, and then beat in 4 eggs, one at a time. Dissolve 1 teaspoon of baking powder in 1/2 cup buttermilk, and add to egg mixture.
In a separate bowl, mix 3 1/2 cups all-purpose flour with 1 pound of chopped orange slice candies, 1 pound of chopped dates, and 2 cups of chopped pecans. Combine 3 1/2 ounces of coconut and the flour with the egg mixture. A strong wooden spoon works best, as this makes a stiff dough. Pat the dough into the prepared tube pan and bake at 250 F for 2 1/2 hours.
Mix 1 cup of fresh orange juice with 2 cups of powdered sugar to make a smooth glaze. Pour the glaze evenly over the hot cake, and allow it to soak in the pan overnight. Remove the cake from the pan just before serving.