This fudgy chocolate cake is the ultimate indulgence! Ultra-rich, moist chocolate cake is baked from scratch and topped with a sweetened, ganache-like glaze. This recipe is baked in a 9 inch cake pan and makes a simple, single-layer chocolate cake.

close-up overhead view of a slice of fudgy chocolate cake being lifted by a cake server

If you love chocolate and you like your cakes ultra decadent and moist, this fudgy chocolate cake is for you! This cake is so rich and chocolatey, just one layer of cake and a simple chocolate ganache-like glaze is all it needs to deliver some serious indulgence. And since it's a one-layer cake, its smaller size makes it perfect for a Valentine's Day celebration at home.

overhead view of a slice of fudgy chocolate cake on a white ceramic plate with a metal fork on a white background

How to Make a Fudgy Chocolate Cake from Scratch

While this cake is not difficult or overly time-consuming to make, it does require you to dirty a few bowls. I promise the extra dishes will be worth it when you take a bite of this rich and fudgy chocolate cake!

Begin by preheating the oven to 350°F and buttering and flouring your 9 inch cake pan. I actually prefer to use cocoa powder instead of white flour for this when baking chocolate cake. If you haven't buttered and floured a cake pan before I explain exactly how to do it in the recipe. Once you've done this, line the bottom of the cake pan with parchment paper.
Next, make the chocolate cake batter. Add chopped chocolate and butter to a large heat-proof bowl. Add boiling water to the bowl to melt the chocolate and butter, then whisk until smooth.
Add sugar and vanilla to the chocolate mixture and whisk until blended. Then add an egg yolk and whisk until combined. (Save the egg white for a later step.)
In a small bowl combine heavy cream and vinegar or lemon juice, stirring to combine. This creates a mixture with a texture and acidity like sour cream. Add baking soda to the cream mixture and stir until well blended. When the mixture puffs up, add it to the chocolate mixture and whisk to combine.
Sift the flour and baking powder into the chocolate mixture and gently stir until blended.
Add the egg white to a medium bowl and beat just until stiff peaks form. Add a bit of the egg white to the chocolate batter and stir until blended before folding in the remaining egg white.
Pour the batter into the prepared pan and bake the cake for 25-30 minutes or until a toothpick inserted into the center of the cake comes out clean. Let the cake cool in the pan for 10 minutes before carefully turning it out onto a wire rack to cool completely.
To make the chocolate glaze, add chopped chocolate, butter, heavy cream, confectioners' sugar, and vanilla to a small saucepan. Whisk the ingredients together over low heat until blended and smooth.
Pour the glaze over the cake and dig in!

close-up overhead view of a slice of fudgy chocolate cake with red and white heart sprinkles on a white ceramic plate

Sour Cream Substitute

Sour cream is often used to add richness and moisture to cake batter, helping to create a moist cake. Because of its acidity, it can also be used to activate baking soda. However, I don't always have sour cream or yogurt on hand (and I don't love having to buy an ingredient to use a small amount of it), so I tested several substitutes when baking this cake.

For this fudgy chocolate cake recipe, sour cream would be responsible for adding moisture and also activating the baking soda, so I needed a substitute that could do both. And since I'm already needing heavy cream for the chocolate glaze, I used heavy cream to create a sour cream substitute.

This cake recipe uses ¼ cup (57 grams) heavy cream combined with 2 tsp. (9 grams) distilled white vinegar (or lemon juice) to create a mixture whose texture is just like sour cream. It adds just the right amount of moisture and acidity to the cake's batter. If you'd prefer, you can use ¼ cup (57 grams) of full-fat sour cream or Greek yogurt in this recipe in place of the heavy cream and vinegar.

side view of fudgy chocolate cake on a pink cake stand with a slice being lifted by a cake server

Why Do We Add Hot Water to Chocolate Cake?

Boiling water is often added to chocolate cake recipes made with cocoa powder in order to "bloom" the chocolate, which brings out the flavor of the chocolate while minimizing any lumps in the cake batter. In this cake, made with chopped chocolate rather than cocoa powder, the boiling water is used to melt the chocolate and butter and also add liquid to the cake batter, which works to create a moist chocolate cake.

overhead view of a slice of fudgy chocolate cake with red and white heart sprinkles on a white ceramic plate

How to Store Fudgy Chocolate Cake

This chocolate cake tastes best the day it's made, as cake will become less moist with time. Leftovers can be stored in an airtight container at room temperature for up to 3 days.

close-up side view of a slice of fudgy chocolate cake on a white ceramic plate

Single Layer Fudgy Chocolate Cake

Author: Allison Ferraro
Prep Time: 40 minutes
Cook Time: 25-30 minutes
Total Time: 1 hour 10 minutes (Does not include time for cake to cool before glazing.)
Yield: 8 servings (1 single-layer 9 inch cake) 1x

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Description

This single-layer fudgy chocolate cake is the ultimate indulgence! Ultra-rich, moist chocolate cake is baked from scratch and topped with a sweetened, ganache-like glaze.

Ingredients

Scale

for the fudgy chocolate cake:

butter (or vegetable shortening) and cocoa powder (or all-purpose flour) for greasing the pan
1 ½ oz. (43 grams) semi-sweet chocolate baking bar, finely chopped
¼ cup (57 grams) unsalted butter, cut into small cubes
½ cup (114 grams) boiling water
1 cup (198 grams) granulated sugar
½ tsp. (2.5 grams) vanilla extract
1 large egg (50 grams), separated
¼ cup (57 grams) heavy cream*
2 tsp. (9 grams) distilled white vinegar or lemon juice*
½ tsp. (3 grams) baking soda
⅞ cup plus 1 Tbsp. (113 grams) all-purpose flour
½ tsp. (2 grams) baking powder

for the chocolate glaze:

2 ½ oz. (71 grams) semi-sweet chocolate baking bar, finely chopped
2 Tbsp. (28 grams) unsalted butter
3 Tbsp. heavy cream (43 grams) heavy cream
½ cup (51 grams) sifted confectioners' sugar
½ tsp. (2.5 grams) vanilla extract

Instructions

Preheat oven to 350°F.
Prepare one 9 inch round cake pan by buttering and flouring the pan. (Coat the interior of each pan with a thin layer of butter (or vegetable shortening), making sure to coat the entire bottom, into the edge, and up the sides. Sprinkle a bit of cocoa powder (or all-purpose flour) into the pan and shake it over the sink so that all of the butter is covered by a dusting of cocoa powder. Dump out any excess cocoa powder.) Place a circle of parchment paper in the bottom of the pan and set the prepared pan aside.
Make the chocolate cake batter. Add the chopped chocolate and cubed butter to a large heat-proof bowl. Pour the boiling water over the chocolate and butter and let the mixture sit for 2 minutes to melt before whisking until smooth.
Add sugar and vanilla to the chocolate mixture, whisking until blended and smooth. Add the egg yolk and whisk until combined. (Reserve the egg white for step #7.)
In a small bowl combine heavy cream and vinegar or lemon juice, stirring to combine. The mixture should have the consistency of sour cream. Add baking soda to the cream mixture and stir until well blended. Let the mixture sit for 30 to 60 seconds; it should puff up as it sits. Add the mixture to the chocolate mixture and whisk to combine.
Sift the flour and baking powder into the chocolate mixture and gently stir until blended.
Add the egg white to a medium bowl and beat just until stiff peaks form; the egg white should be stiff but still moist and not dry. Add a spoonful of the beaten egg white to the chocolate batter and stir until well blended. Add the remaining beaten egg white to the bowl with the batter and gently fold the egg white into the batter just until combined.
Bake the cake. Pour the batter into the prepared pan and bake the cake on the center rack for 25-30 minutes or until a toothpick inserted into the center of the cake comes out clean. Let the cake cool in the pan for 10 minutes before carefully turning it out onto a wire rack to cool completely.
Make the chocolate glaze. Add all of the ingredients to a small saucepan over low heat. Continuously whisk the ingredients until blended and smooth. Remove the pan from heat.
Let the glaze cool slightly in the pan about 5 minutes, whisking periodically, so the glaze thickens slightly but is still pourable. Pour the glaze over the cake and use an offset spatula to spread the glaze, if desired.

Notes

This recipe is adapted from The Silver Palate's Chocolate Cake recipe shared by NYT Cooking.

Storage: This chocolate cake tastes best the day it's made, as cake will become less moist with time. Leftovers can be stored in an airtight container at room temperature for up to 3 days.

*When testing this recipe I used a mixture of heavy cream and distilled white vinegar to create a sour cream substitute using ingredients that I already needed for the glaze or commonly have on hand so that I wouldn't have to buy sour cream to use just a small amount in this cake. If you'd prefer, you can use ¼ cup (57 grams) of full-fat sour cream or Greek yogurt in place of the heavy cream and vinegar/lemon juice in the cake batter.

Category: Dessert
Method: Baking
Cuisine: American

Keywords: chocolate cake, fudgy, single-layer, one layer, chocolate glaze

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