American German Chocolate Cake, made to the Hungarian taste

Every year for his birthday, my mom would make my dad a German Chocolate cake with Baker's chocolate. I don't recall my mom using the classic coconut frosting; instead there was a chocolate frosting with those chocolate sprinkles on top. It is always ironic that my Hungarian dad's favorite cake was an Americanized chocolate cake without the frosting it is famous for. 

This is my re-creation of that cake. The cake recipe is from Tastes Better From Scratch which is paired with a chocolate buttercream frosting from Sugar Spun River.  I have also used a cocoa-based buttercream from Add a Pinch which is good but sweeter than I would like for this cake. (If you don't have chocolate bars, use Add a Pinch's with less powdered sugar. I've included it at the end of this recipe.) Top with shaved chocolate. I like dark chocolate for this (75-90%).

CAKE
2 cups granulated sugar
½ cup oil (vegetable or canola oil)
2 teaspoons vanilla extract
2 large eggs
1 cup buttermilk

1¾ cups all-purpose flour
¾ cup unsweetened cocoa powder
1½ teaspoons baking powder
1½ teaspoons baking soda
1 teaspoon salt

1 cup boiling water

BUTTERCREAM (using chocolate bars or chips). I always seem to use a double batch of the buttercream so the amount below is for a double batch. If you have too much, it's just an opportunity to make cupcakes! If you want a single batch, the original recipe is here.

12 oz semisweet chocolate (I use 75%), chopped into small pieces of roughly the same size OR 2 cups semisweet chips (340g)
2 cup unsalted butter (4 sticks), softened to room temperature 
4 cups powdered sugar, sifted (448g)
2 tsp vanilla
1/2 tsp salt (omit if using salted butter)
4 tbsp heavy cream (60ml)

MAKING THE CAKE

1. Heat oven to 375°F. Grease two 8 or 9-inch round baking pans I prefer 8" so the cakes are taller which is easier to cut in half. Cut a round piece of wax or parchment paper for the bottom of the pan also to make sure the cake comes out easily. Parchment/wax paper works better for not sticking than oil + flour.
2. Stir together flour, baking powder, baking soda and salt in a separate bowl.
3. Add cocoa to hot water and mix well. Set aside until needed.
4. Combine oil and sugar in a mixing bowl and beat on medium until creamy (about 2-3 mins). Add the eggs, one at a time and beat on medium. Add the vanilla and beat until mixed.
5. Add half the flour mixture to the oil and sugar. Add half the buttermilk and mix on low to combine. Continue adding the second half of the flour and buttermilk.
6. Stir in the cocoa mixture. The batter will be very thin. Pour it into the prepared pans.
7. Bake for 25 - 35 minutes (depending on your cake pan size. The 9'' pan takes less time to bake) or until a toothpick inserted in center comes out clean or with few crumbs. Cool. Using a plastic knife or offset metal spatula, loosen the edges of the cake and then carefully remove from pan. The cake may still stick to the pan, which is ok. Just save the piece and reattach it to the cake when frosting. 
8. Wrap in plastic wrap and place in freezer, leaving the parchment paper on until you frost it.

MAKING THE BUTTERCREAM (with chocolate bars or chips). The buttercream may be made a few days in advance and kept covered in the refrigerator. Make sure to allow time for the frosting to come back to room temp before using it - it needs to be spreadable which took a couple of hours in my kitchen.

1. Place the chocolate in a microwave-safe bowl and microwave at 50% for 30 seconds. Stir well. Return chocolate to microwave and heat for another 15 seconds at 50% and stir again. Continue heating chocolate for 15 seconds at 50%, stirring after each, until chocolate is melted and smooth. It took about 1 minute in total for 2 chocolate bars.
2. Allow chocolate to cool until lukewarm, stirring occasionally, so that it will not melt the butter when added.
3. Sift the powdered sugar through a strainer so the frosting will not be lumpy.
4. While the chocolate is cooling, place the butter in a mixing bowl. Use a stand mixer or electric mixer to beat on high until creamy. Butter turns lighter as it is beaten -- you are looking for it to become visibly lighter. It make take a couple of minutes. 
5. Add the tepid melted chocolate slowly to the butter and continue mixing.
6. Gradually add powdered sugar, scraping down the sides and bottom of bowl occasionally so that ingredients are well combined.
7. Sprinkle in salt and vanilla extract, and mix well.
8. With mixer on low, gradually add heavy cream to frosting. Taste and add more cream, sugar, or chocolate as desired for taste and consistency. Gradually increase speed to high and beat for 30 seconds. 
9. Pipe or spread frosting onto the cake layers.

ASSEMBLING THE CAKE

1. Remove cakes from the freezer and let them thaw about 30 minutes to an hour.  I use a flat serrated knife that is wider than than the cake. Place one hand flat on the top of the cake and with gentle sawing motion, cut through the cake, creating the 2 layers. Repeat with the other cake. You will have 4 layers at this point. For fancy cakes, I use 6 layers.
2. Smooth a thin layer of chocolate buttercream over the first cake layer. Stack the second cake round on top, and repeat with remaining layers. Pro tips:  (1) I will flip the best looking "bottom" over and save it for the top layer of the cake. (2) Frost a "skim coat" on the top and sides and put back in the freezer for 30 mins if you have time. Refreezing at this point allows you to put another layer of frosting on without crumbs getting embedded.
3. The cake can be completely frosted, left skim-coated on the sides, or left with the sides bare. Garnish with chocolate sprinkles or shavings from a good quality chocolate bar (use a vegetable peeler to shave the chocolate bar or a grater for finer shavings).

NOTES

• Freezing Instructions: After baking the cake layers, allow them to cool completely, then wrap them well in plastic wrap and stick each layer in a ziplock freezer bag. Freeze for up to three months. Frost the cakes when they are frozen--they are much easier to frost this way! 
• The assembled German Chocolate Cake can also be covered well and frozen for 2-3 months (I recommend slicing the cake and wrapping each slice really well in plastic wrap, then placing in a freezer-safe container, for best results). Allow to come to room temperature before serving.

ALTERNATE BUTTERCREAM WITH COCOA POWDER

1½ cups butter softened
1 cup unsweetened cocoa powder
5 cups confectioner’s sugar (would definitely start with 4 cups and add if needed)
½ cup milk
2 teaspoons vanilla extract

BUTTERCREAM INSTRUCTIONS

1. Add cocoa powder to a large bowl or bowl of stand mixer. Whisk through to remove any lumps.
2. Cream together butter and cocoa powder until well-combined.
3. Add sugar and milk to cocoa mixture by adding 1 cup of sugar followed by about a tablespoon of milk. After each addition has been combined, turn mixer onto a high speed for about a minute. Repeat until all sugar and milk have been added.
4. Add vanilla extract and combine well.
5. If frosting appears too dry, add more milk, a tablespoon at a time until it reaches the right consistency. If it appears to wet and does not hold its form, add more confectioner’s sugar, a tablespoon at a time until it reaches the right consistency.