How is this cake so moist?

This cake is the most moist chocolate cake I've ever had. The secret ingredients for that are brown sugar, oil, eggs, buttermilk and boiling hot water. Brown sugar adds more softness and moisture than granulated sugar. Oil reduces the gluten formation in your batter, which makes the cake more moist as compared to using butter as a fat. Eggs strengthen the binding of the cake and add moisture along with contributing to the fat content in the cake. Buttermilk has a higher fat content than whole (full-fat) milk, thus adding moisture to your cake. For hot water, read below!

Why is boiling hot water important to make this cake?

I believe that adding hot water is what makes this recipe so delicious & moist. Hot water is added at the very end of the process. The reason for this is that after all the other ingredients are mixed, the flour is very effectively coated with fat (oil and eggs). Adding water at this point reduces the amount of gluten that can be formed, thus making the cake more moist. The reason the water is hot is because a hot liquid along with espresso powder helps bloom the cocoa powder, creating a deeper, more rich chocolate flavour.

How to avoid dome shaped cakes?

Whether you're making a layer cake or a single layer cake, flat tops are always desirable. The reason why cakes dome that your cake pan heats up much faster than the rest of the cake causing the edges to set before the cake has risen fully, and as the rest of the cake cooks the centre rises and creates a dome. To avoid this from happening you want to protect the edges of your cake pan. To do this, you can wrap cake strips, foil, or a damp cloth around the edges of your cake pan. Be careful with the damp cloth as it might start burning after it completely dries out. This trick will ensure you get flat tops always!

Can I make cupcakes or a layer cake instead?

Yes you most definitely can. This recipe will yield 12 large cupcakes. If you want to make a layer cake, double or triple the quantity of ganache depending on the way you want to frost it. You can either double this batter and form two very thick cake layers or you can also divide this batter into two 6-inch cake pans. If you want to make a 9-inch cake, this batter will yield one 9-inch cake. You can double it if you want a 9-inch layer cake.

Single Layer Chocolate Ganache Buttermilk Cake

Description

This single layer chocolate ganache buttermilk cake is my version of the best chocolate cake! It is every chocolate lovers dream and will brighten up your day in no time. Even though its diameter is small, this is a very thick chocolate cake. I use four different tricks that are known to create the best qualities most seek in a chocolate cake. They each add to the softness, and moistness or enhance the flavor of chocolate in the cake. By far, I’ve never had luck with coming across a recipe that uses all of these tips and tricks. The flavor and texture of this cake is thus unparalleled by any other!

Ingredients

Scale

Chocolate Cake

1 cup (125g) all-purpose flour, sifted
6 tablespoons (38g) natural unsweetened cocoa powder, sifted
1 teaspoon baking powder
¾ teaspoon baking soda
½ teaspoon salt
½ teaspoon espresso powder
½ cup (100g) granulated sugar
½ cup (110g) light or dark brown sugar
¼ cup (60ml) vegetable or canola oil
1 large egg, at room temperature
1 teaspoon pure vanilla extract
½ cup (120ml) buttermilk, at room temperature
½ cup (120ml) boiling hot water

Chocolate Ganache Buttercream

½ cup (80g) dark chocolate chips or bars, chopped
¼ cup (56g) unsalted butter, cut into cubes
½ cup (50g) powdered or confectioners’ sugar
¼ teaspoon salt
½ teaspoon espresso powder

Instructions

Chocolate Cake

Preheat oven to 350°F (177°C). Grease a 6×2 inch cake pan, line with parchment paper, then grease the parchment paper. Parchment paper helps the small cake seamlessly release from the pan. I usually grease it with nonstick spray. Set aside.
Sift the flour and cocoa powder together into a large bowl. To that add baking powder, baking soda, espresso powder, and salt. Whisk all of them together.
In another bowl, whisk together the granulated sugar, brown sugar, oil, egg, vanilla extract, and buttermilk.
Add the dry ingredients into the wet ingredients about 4-5 tablespoons at a time and whisk until combined. Repeat until all dry ingredients are added. The cake batter will be slightly thick.
To this, add boiling hot water and whisk to combine.
Pour the cake batter evenly into prepared cake pan.
Bake for around 27-30 minutes or until the cake is baked through. To test for doneness, insert a toothpick into the center of the cake. If it comes out clean, it’s done. If your toothpick is unable to reach the bottom of your pan, use a cake tester and cover up the hole it creates with the chocolate ganache.
Allow cake to cool in the cake pan completely on a wire rack before frosting.

Chocolate Ganache Buttercream

While the cake is baking, prepare the chocolate ganache buttercream.
In a large microwaveable bowl, add the chocolate (preferably chopped). Add cubed unsalted butter to this bowl.
Microwave the mixture in 30 second intervals whisking vigorously in between. Repeat until the chocolate and butter are completely melted. You can also use a double boiler or follow the ‘bain-marie’ method for doing this.
Let it cool down at room-temperature for about 5 minutes. It will thicken as it cools. To this add powdered sugar 4-5 teaspoons spoons at a time. Whisk to incorporate the sugar thoroughly. Repeat until all the sugar is added.
Add in the salt and espresso powder. Whisk to combine. Your chocolate ganache buttercream will be thick at this point.
Pour the buttercream on top of the cooled cake. Using an offset spatula, spread it on the cake evenly.
Let the cake chill in the refrigerator for atleast 30-minutes before slicing. Enjoy!
Store cake in an airtight container in the refrigerator for upto a week.

Notes

Boiling hot water reduces gluten formation thus making the cake more moist. It also helps enhance the flavor of chocolate in the cake just like espresso powder and vanilla extract.
If you’re in a pinch and don’t have buttermilk in hand, I have a DIY substitute for you. Add 1 teaspoon of lemon juice in half cup. You can double or half this as required. Fill that cup with whole milk to the top. Mix and let it sit for 5 minutes. That’s it, your buttermilk is ready. Your muffins may not turn out marvellous, but they will still be delicious!
I highly recommend investing in an oven thermometer and a kitchen scale. Baking at accurate temperatures and weighing your ingredients correctly ensure that you can replicate the recipes perfectly and enjoy the best flavors.

Prep Time: 30 minutes
Cook Time: 30 minutes
Category: Chocolate, Cake, Dessert
Cuisine: American

Keywords: chocolate ganache, chocolate buttercream, dark chocolate cake, single layer cake, silky chocolate ganache