Rich Chocolate Hazelnut Cake

This one-bowl chocolate hazelnut cake tastes deeply nutty and bittersweet, with a tender crumb that stays moist for days. A glossy ganache slicked over the top gives it a finished look without any special decorating skills.

If you like the flavor of Nutella but want something homemade, this is where you start. The cake itself gets its richness from cocoa and finely ground hazelnuts, and the warm ganache puddles into every crack and crevice.

Why This Cake Keeps Working

The texture is the real win here. Oil and buttermilk make it soft straight out of the oven and keep it that way. There is no creaming, no mixer, and the batter comes together fast with a whisk and a bowl.

Ground hazelnuts do a lot of the heavy lifting for flavor. They toast slightly as the cake bakes, so you get a nuttiness through every bite that tastes more roasted than raw. The ganache is just chocolate and cream, poured over while warm so it sets smooth and shiny.

Ingredients

• 1 ½ cups all-purpose flour: spooned and leveled, not scooped
• ½ cup unsweetened cocoa powder: Dutch-process gives a deeper color
• 1 tsp baking soda
• ½ tsp fine sea salt
• 1 cup granulated sugar
• ½ cup packed light brown sugar
• 1 cup finely ground hazelnut meal: store-bought or toasted hazelnuts ground in a food processor
• 1 cup buttermilk, at room temperature
• ½ cup vegetable oil: any neutral oil works
• 2 large eggs, at room temperature
• 2 tsp vanilla extract
• ½ cup boiling water: helps bloom the cocoa

For the ganache

• 4 oz dark chocolate, chopped: 60-70% cacao
• ½ cup heavy cream
• 1 tbsp unsalted butter
• ¼ cup toasted chopped hazelnuts: for finishing

Variations / Substitutions

• Swap buttermilk: use plain whole milk yogurt thinned with a splash of milk
• Make it gluten-free: substitute a 1:1 gluten-free flour blend, and add ½ tsp xanthan gum if your blend lacks it
• Add espresso: stir 1 tsp instant espresso powder into the boiling water to deepen the chocolate
• Use almonds: replace hazelnut meal with an equal amount of almond flour for a milder nutty cake
• Skip the ganache: dust with powdered sugar or spread with a jar of good hazelnut chocolate spread while the cake is still warm

This cake shares a lot of technique with a classic devil’s food cake, which leans all the way into cocoa without the nutty note.

How to Make Rich Chocolate Hazelnut Cake

Step 1: Mix the Dry Ingredients

Preheat your oven to 350°F (175°C) and line the bottom of a 9-inch round cake pan with parchment paper, then grease the sides lightly. In a large bowl, whisk together the 1 ½ cups flour, ½ cup cocoa powder, 1 tsp baking soda, ½ tsp salt, 1 cup granulated sugar, ½ cup brown sugar, and 1 cup hazelnut meal until no lumps remain.

The mixture will smell a little earthy from the hazelnut meal. Break up any visible clumps of brown sugar with your fingers or the back of the whisk.

Step 2: Stir in the Wet Ingredients

Add the 1 cup buttermilk, ½ cup oil, 2 eggs, and 2 tsp vanilla right into the dry ingredients. Whisk until just smooth, then stream in the ½ cup boiling water and whisk again until the batter is uniform and glossy.

The batter will be thin, more like a thick pancake batter than a cookie dough. That is exactly what you want. A few small lumps are fine; overmixing will make the cake tough.

Step 3: Bake the Cake

Pour the batter into the prepared pan and tap the pan gently on the counter once to release any large air bubbles. Bake on the middle rack for 35 to 40 minutes, until a toothpick inserted in the center comes out with a few moist crumbs clinging to it.

The edges will pull away from the pan just slightly. Let the cake cool in the pan for 10 minutes, then turn it out onto a wire rack to cool completely before you add the ganache.

Step 4: Pour the Ganache and Top with Hazelnuts

While the cake cools, place the 4 oz chopped dark chocolate and 1 tbsp butter in a heatproof bowl. Heat the ½ cup heavy cream in a small saucepan over medium heat until it just begins to simmer, then pour it over the chocolate. Let it sit for 2 minutes, then stir slowly from the center outward until the ganache is dark and glossy.

Set the cooled cake on a serving plate and pour the warm ganache right over the center, nudging it toward the edges with a spatula without overworking it. Scatter the ¼ cup toasted chopped hazelnuts over the top before the ganache sets.

Tips for a Better Crumb and Finish

• Toast your hazelnuts, even if you bought them pre-toasted. A quick 5 minutes in a dry pan wakes up the oils and makes the nuttiness sharper.
• Use room temperature buttermilk and eggs. Cold ingredients can seize the oil and create a dense band at the bottom of the cake.
• Do not open the oven door before the 30-minute mark. The steam helps the cake rise, and a draft early on can cause it to sink.
• For the shiniest ganache, stir only until combined. Overworking cools it down too fast and can make it grainy.

Bake times by pan:

Keeping the Cake Fresh

Refrigerate the cake in a covered container for up to 5 days. The ganache firms up when cold, so let slices sit at room temperature for 20 minutes before eating.

Reheating is not necessary, but a 10-second zap in the microwave softens the ganache if you want it fudgy again.

Frequently Asked Questions

Can I use hazelnut spread instead of making ganache?

Yes, warm ¾ cup of hazelnut chocolate spread in a small saucepan with 2 tbsp heavy cream and stir until pourable.

Can I make this cake without hazelnut meal?

You can replace the hazelnut meal with an equal amount of all-purpose flour, but the cake will lose its nutty backbone and will taste like a plain chocolate cake.

What if my hazelnut meal is coarse?

A coarse grind will still work, but you may feel a slight graininess in the crumb. For a smoother texture, pulse it in a food processor until fine.

Can I freeze this cake?

Yes, freeze the unglazed cake wrapped tightly for up to 2 months. Glaze after thawing to keep the ganache shiny.

My cake sank in the middle, what happened?

It likely needed a few more minutes in the oven, or the oven temperature ran low. Use an oven thermometer to check, and test the center with a toothpick.

Chocolate Hazelnut Cake Recipe

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 35 minutes mins

Total Time 50 minutes mins

Servings: 8 servings

Calories: 432

Ingredients Method Notes

Ingredients

  

• 1 ½ cups all-purpose flour
• ½ cup unsweetened cocoa powder
• 1 tsp baking soda
• ½ tsp fine sea salt
• 1 cup granulated sugar
• ½ cup packed light brown sugar
• 1 cup finely ground hazelnut meal
• 1 cup buttermilk, at room temperature
• ½ cup vegetable oil
• 2 large eggs, at room temperature
• 2 tsp vanilla extract
• ½ cup boiling water
• 4 oz dark chocolate, chopped
• ½ cup heavy cream
• 1 tbsp unsalted butter
• ¼ cup toasted chopped hazelnuts

Method

 

1. Preheat oven to 350°F (175°C). Line a 9-inch round cake pan with parchment and grease the sides. Whisk flour, cocoa, baking soda, salt, sugars, and hazelnut meal in a large bowl.
2. Add buttermilk, oil, eggs, and vanilla. Whisk until smooth, then stir in boiling water until glossy.
3. Pour batter into pan, tap once on the counter, and bake 35 to 40 minutes until a toothpick has moist crumbs. Cool 10 minutes in pan, then turn out to cool completely.
4. Heat cream until simmering, pour over chopped chocolate and butter, wait 2 minutes, then stir until smooth. Pour ganache over cooled cake and top with toasted hazelnuts.

Notes

If your kitchen runs cool, the ganache may thicken before it hits the cake. Warm it gently over a double boiler for a few seconds to loosen it back up. The cake tastes even better the next day as the flavors settle.