Name: Rich & Moist Chocolate Fudge Cake (1 Hour, No Mixer Needed)
Prep time: 35 min
Cook time: 25 min
Total time: 1 h
Ingredients: 140 g (1 cup) all-purpose flour; 220 g (1 cup) granulated sugar; 40 g (1/2 cup) dutch process cocoa powder, sifted; 1 teaspoon baking soda; 1/2 teaspoon baking powder; 1/2 teaspoon salt; 120 g (1/2 cup) sour cream, at room temperature; 120 g (1/2 cup) hot coffee; 50 g (1/4 cup) vegetable oil; 1 large egg, at room temperature; 1 large egg yolk, at room temperature; 2 teaspoons pure vanilla extract; 113 g (4 ounces) semi-sweet chocolate, chopped; 75 g (5 tablespoons) unsalted butter; 120 g (1/2 cup) heavy cream; 450 g (1 pound) powdered sugar; 2 teaspoons pure vanilla extract

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This ultra-moist Chocolate Fudge Cake is a weeknight favorite! It’s an easy one-layer cake made with hot coffee and sour cream for a decadent and moist crumb. It’s topped with a rich fudge frosting for double the indulgence. No mixer needed–just a few simple ingredients, and it’s ready in one hour!

Single layer square chocolate fudge cake topped with fudge frosting cut into squares set on a parchment paper.

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Weeknights are pretty chaotic around here, but that doesn’t stop us from baking! So quick and easy cakes are a must, especially something as decadent as this cake. Prep is simple, cleanup is easy, and you’ll have a dessert that satisfies any chocolate craving.

This is a single-layer variation of my fluffy chocolate fudge cupcakes. We’re talking rich and decadent, yet with a light, irresistible texture. It bakes beautifully in a 9-inch square baking pan, making it an easy, no-fuss cake for any occasion.

And if you like more one-hour desserts, be sure to check out my white chocolate chip brownies and easy chocolate sheet cake recipes (both fit perfectly into busy evenings!).

Key Ingredient Notes & Substitutions

Chocolate fudge cake ingredients in bowls on a baking sheet.

Chocolate fudge frosting ingredients on a baking sheet.

Cocoa powder: Adds a rich chocolatey flavor to the cake. I prefer Dutch-processed cocoa powder for its smooth, rich flavor. Using natural cocoa will work, but the cake will taste slightly more bitter. Make sure you sift the cocoa powder to remove any clumps.
Sour cream: Full-fat sour cream gives this cake its ultra-moist texture. Greek yogurt works well too, for an easy swap, but low-fat versions won’t give you the same results.
Strong hot coffee: This will enhance the chocolate flavor without adding actual coffee flavor to the cake. Use regular or decaf coffee, or you can omit the coffee and swap it with hot water.
Chocolate: I recommend using a chopped semi-sweet chocolate baking bar for the frosting. Chocolate chips have stabilizers to maintain their shape, whereas chocolate bars melt smoothly, creating a more decadent frosting.
Heavy cream: I always use heavy cream for a rich, creamy frosting texture. You can swap it for whole milk, but I wouldn’t recommend another type of milk. The fat in the milk helps the frosting set.

Please see the recipe card for the complete list of ingredients and measurements.

One Batter, Two Ways

Bake a bundt cake: Pour the fudge cake batter into a greased and flour 10x3 inch bundt pan. Start checking the cake around the 30-minute baking mark.
Make cupcakes: Fill 18 cupcake liners halfway and bake for 18-20 minutes or until the tops spring back when pressed lightly.

Step-By-Step How to Make a Fudge Cake

Dry ingredients whisked in a glass mixing bowl for chocolate fudge cake.

Combine dry ingredients. Either sift or whisk together the flour, sugar, cocoa powder, baking soda, baking powder, and salt in a large bowl.

Wet ingredients whisked in a glass mixing bowl for chocolate fudge cake.

Mix wet ingredients. In a separate bowl, whisk the sour cream, coffee, vegetable oil, egg, yolk, and vanilla until smooth.

Chocolate fudge cake batter in a glass mixing bowl.

Combine ingredients. Pour the wet ingredients into the dry ingredients, then whisk everything together for about 1 minute.

Chocolate fudge cake batter in a 9x9 square baking pan lined with parchment paper.

Fill and bake. Add the batter into a parchment-lined 9-inch square pan and bake for about 25 minutes.

Butter, chocolate, and heavy cream in a glass bowl set over a small pot of simmering water for fudge frosting.

Make the frosting. Put the chocolate, butter, and heavy cream in a bowl set over a small pot of simmering water. You want to stir frequently until the mixture is completely melted and smooth.

Fudge frosting in a glass mixing bowl cooling to set up before using to decorate a cake.

Add the sugar and vanilla. Pour the chocolate into a large bowl and whisk in the powdered sugar and vanilla until smooth. Stir the mixture occasionally while it cools until it thickens to a frosting consistency.

My Tried & Trusted Tips for Making This Cake

Use a light-colored aluminum baking pan: This is your best bet for even baking. Using a dark coated pan will cause your cake to bake too quickly, and a glass pan will need extra time.
Check your cake for doneness: The edges should start to pull away from the sides of the pan, and when you gently push in the center of the cake, it should bounce back. You can also use a toothpick to check if your cake is done baking (when poked in the center of the cake, it should come out mostly clean).
Refrigerate the cake: To quickly cool the cake for frosting, you can set it uncovered in the refrigerator for about 15 minutes before adding a layer of fudge frosting.
Use the frosting while it’s still soft: You’ll notice that as it sits, it begins to set (which is what we want!). Once it’s cooled yet still soft, spread it over your fudge cake.

Bake Tonight, Serve Tomorrow

This cake stays incredibly moist overnight and can be baked the evening before you serve it. Once it’s cooled, cover it and keep it on the counter at room temperature. You’ll want to make the fudge frosting just before decorating the cake, whether that’s the night before or just before serving.

More Easy 1 Layer Cakes

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