Begin by preheating the oven to 350 degrees Fahrenheit. Line four seven-inch or three eight 8-inch pans with parchment rounds, and spray with non-stick spray.

Add the sugar and butter into the bowl of a stand mixer, and mix on high for 1 minute with a whisk attachment. The mixture should become light in color.

Add in the eggs, one at a time. Then add baking soda, baking powder, and salt. Mix on high for another minute.

In a separate bowl, combine the cup of hot water, and black cocoa. Whisk until no clumps remain. Gently stir in the buttermilk and red wine.

Next, add 1 cup of flour to the butter/egg mixture. Scrape the sides of the bowl with a spatula, to ensure the flour is fully incorporated.

Pour in half of the cocoa mixture, and gently pulse the mixture to incorporate the liquid (if you don't, you'll end up splattering the cocoa mixture all over your kitchen!)

Mix in the 2nd cup of flour, at a low speed. Pour in the remaining cocoa mixture, and again gently pulse, then mix on low until fully combined.

Add in the last cup of flour, and mix on low until the flour is incorporated. Mix on high for 30 additional seconds, to incorporate a bit more air into the batter.

Evenly divide between the prepared pans. I like to use a kitchen scale to ensure each pan has exactly the same amount of batter.

Bake for 32-35 minutes, or until a toothpick comes out clean.

Allow layers to cool in the pans for about 10 minutes, then run an offset spatula around the edge of the pans to help separate the layers from the pans.

Place the pans in the freezer for about 45 minutes, to accelerate the cooling process. Once the layers are fully cooled, carefully flip the pans and remove the layers from the pans.

Use a serrated knife to level the tops of the layers, and then frost as desired.

While the cake layers bake and cool, make the vanilla buttercream frosting.

Beat the butter on a medium speed for 30 seconds with a paddle attachment, until smooth. Gradually mix in the powdered sugar and heavy cream on a low speed.

Once fully mixed, add the vanilla and salt, and beat on low until the ingredients are fully incorporated and the desired consistency is reached. 

If the frosting is too thick, add in additional cream (1 teaspoon at a time). If the frosting is too thin, add in more powdered sugar (a quarter of a cup at a time).

Place half the frosting in a separate bowl, and cover it with plastic wrap.

Add the red wine to the remaining frosting, and mix until combined. If desired, add maroon gel food coloring to make a wine-colored frosting. Cover with plastic wrap and set aside.

Place water and sugar in a pot.

Heat over high heat, stirring occasionally until the mixture just begins to boil.

Remove from heat, and allow the mixture to cool for 10 minutes.

Add in red wine, and set aside.

Heat heavy cream in a heat-proof bowl in the microwave for 45 seconds, until it's just beginning to bubble. Gently pour white chocolate chips into the heavy cream, making sure they are fully covered with cream. Allow mixture to sit for 1 minute.

Stir slowly until the cream and white chocolate are combined. Some bits of chocolate may not be fully melted yet. Heat the mixture again for 20 seconds, and stir. Repeat as necessary until all the chocolate bits are fully melted and incorporated.

Add in the maroon gel food coloring.

Allow to cool until desired viscosity is reached (barely warm to the touch).

If it seems too thin or thick, you can add a touch more chocolate chips or heavy cream! The type of cream and white chocolate that you use can affect the consistency, so feel free to adjust as needed.

Carefully soak the cake layers with the red wine simple syrup using a kitchen brush.

Stack and frost cake layers on a greaseproof cake board, using a dab of frosting to help stick the first cake layer to the board.

Add an even layer of red wine buttercream between each cake layer.

Spread a thin coat of red wine frosting around the cake, to fully cover the cake layers. Smooth using a bench scraper, then chill the cake in the fridge (10 minutes) or freezer (5 minutes) until the frosting is firm to the touch.

Add a second, thicker layer of uncolored, vanilla frosting to the cake, and smooth using a bench scraper.

Gently press the chocolate sprinkles around the base of the cake.

Chill the cake in the fridge (20 minutes) or freezer (5 minutes) again, until the frosting is firm to the touch.

Top the cake with a small mound of frosting, and cover the top of the cake with the red wine ganache. Be careful as you cover the top of the cake so that none of the ganache runs down the sides.

Add the red wine-colored drips around the sides of the cake using a plastic squirt bottle or a spoon.