Preheat the oven to 350° F. Grease 2 9-inch round cake pans with nonstick baking spray.
In a large bowl, sift the flour, cocoa powder, sugar, baking soda, baking powder, and salt. Whisk until combined.
Add eggs, oil, water, and wine, and whisk until just combined. Add sour cream and whisk until fully combined. Be sure not to overmix.
Divide the batter evenly between the 2 9-inch cake pans. Bake for 30 to 35 minutes.
In a microwave-safe bowl, heat heavy cream in 20-second increments until hot but not boiling. Add chopped chocolate and let sit 5 minutes, then stir. Place in the refrigerator to chill while the cake is baking.
In the bowl of a stand mixer, mix the softened butter and powdered sugar for about 2 minutes. Add cocoa powder, milk, vanilla, and salt, and mix for 5 minutes until fully combined. If the frosting is too stiff, add an additional tablespoon of milk.
To assemble the cake, cut each 9-inch cake in half to make 4 layers. Lay the first cake layer on your cake plate and spread a thin layer of ganache over it. Next, dollop icing over the ganache, then spread evenly. Repeat for the other 2 layers. Add the last cake layer and use the remaining frosting for the sides and top of the cake.
Add Harry and David truffles to the top of the cake for a beautiful finish.