This Belgian chocolate cake is the one I reach for when I want a dessert that tastes deeply of dark chocolate and stays tender for days. It does not fuss with layers or elaborate fillings, just a soft crumb and a glossy ganache that sets like silk.

The batter uses real melted Belgian chocolate and the frosting is nothing more than chocolate and cream. That straightforwardness is what makes it work every time, even on a busy weeknight.

What Makes This Cake So Reliable

The chocolate flavor comes from a bar of dark Belgian chocolate with at least 60% cocoa, melted right into the batter. That gives the crumb a richness and intensity that cocoa powder alone just cannot match.

Oil and buttermilk replace some of the butter you might expect, so the cake stays moist even straight from the fridge. The ganache is a quick pour-over affair that firms up enough to cut cleanly but never gets hard or grainy.

Ingredients

200 g (7 oz) dark Belgian chocolate (at least 60% cocoa): the better the chocolate, the deeper the flavor; pick one you enjoy eating on its own
115 g (½ cup) unsalted butter: for melting with the chocolate; salt in the butter balances the sweetness
200 g (1 cup) granulated sugar
120 ml (½ cup) vegetable oil: a neutral oil keeps the cake moist without adding strong flavor
2 large eggs, at room temperature: cold eggs can seize the warm chocolate mixture; pull them out 30 minutes ahead
240 ml (1 cup) buttermilk, at room temperature: its tang softens the chocolate’s edge and makes the crumb tender
1 tsp vanilla extract
150 g (1¼ cups) all-purpose flour
60 g (½ cup) unsweetened cocoa powder: use a dark cocoa if you have it, but any natural or Dutch-process works
1½ tsp baking powder
½ tsp baking soda
½ tsp fine sea salt
120 g (4½ oz) dark Belgian chocolate, finely chopped: for the ganache
120 ml (½ cup) heavy cream: for the ganache

Variations and Substitutions

Semi-sweet chocolate: swap in a 50% cocoa chocolate for a slightly sweeter cake; reduce the sugar by 2 tbsp to keep the balance.
Dairy-free ganache: replace the heavy cream with full-fat canned coconut milk, heated the same way; the result is a touch softer but still glossy.
Add espresso powder: stir 1 tsp instant espresso powder into the hot cream for the ganache; it deepens the chocolate flavor without tasting like coffee.
Swap the frosting: skip the ganache and dust the cake with powdered sugar or spread it with a simple vanilla buttercream when cool.

If you love this cake, try my Classic Vanilla Bean Cheesecake.

How to Make Dark and Moist Belgian Chocolate Cake

Step 1: Mix the Batter

Preheat the oven to 350°F (175°C) and grease an 8-inch round cake pan, lining the bottom with parchment paper. Chop the 200 g dark Belgian chocolate and place it in a heatproof bowl with the 115 g butter. Melt them together over a pan of barely simmering water, stirring occasionally, then set the bowl aside to cool for about 5 minutes.

Whisk the 200 g sugar and 120 ml oil into the melted chocolate mixture until smooth. Add the 2 eggs one at a time, whisking well after each, then stir in the 240 ml buttermilk and 1 tsp vanilla. In a separate bowl, sift the 150 g flour, 60 g cocoa powder, 1½ tsp baking powder, ½ tsp baking soda, and ½ tsp salt. Fold the dry ingredients into the wet mixture with a spatula until just combined; the batter will be glossy and thick.

You will see a few tiny lumps of cocoa, and that is fine. Stop folding the moment no dry streaks remain, or the cake can turn tough.

Step 2: Bake the Cake

Scrape the batter into the prepared pan and smooth the top. Bake on the middle rack for 28 to 32 minutes, until a toothpick inserted in the center comes out with a few moist crumbs clinging to it.

The top will look set and feel springy under a light touch, and the edges will have pulled away from the pan by about 2 mm. Let the cake cool in the pan for 10 minutes, then turn it out onto a wire rack to cool completely.

Step 3: Whisk the Ganache

While the cake cools, place the 120 g finely chopped chocolate in a medium bowl. Heat the 120 ml heavy cream in a small saucepan over medium heat just until it begins to steam and small bubbles appear at the edges; do not let it boil.

Pour the hot cream over the chocolate and let it sit untouched for 2 minutes. Whisk gently from the center outward until the mixture becomes smooth and glossy. The ganache will be pourable but thick enough to coat the back of a spoon; set it aside to cool at room temperature for about 10 minutes so it firms up slightly.

Step 4: Frost and Slice the Cake

Place the completely cooled cake on a serving plate. Pour the ganache over the center and use an offset spatula or the back of a spoon to nudge it to the edges, letting a few drips run down the sides if you like. Let the ganache set for about 15 minutes before slicing.

Cut the cake with a sharp, warm knife and serve the slices on their own or with a dollop of whipped cream. The ganache will hold a clean edge and the crumb underneath stays dark and moist.

A Few Notes Before You Start

Bring eggs, buttermilk, and chocolate to room temperature before you begin; cold ingredients can make the batter seize and the melted chocolate turn grainy.
Spoon flour into your measuring cup and level it off rather than scooping directly from the bag, which packs in too much flour and dries out the cake.
Do not overmix after you add the flour; fold by hand and stop as soon as the streaks disappear. Overworking the batter develops gluten and gives you a dense, tough crumb.
Make the ganache while the cake bakes, then let both cool side by side; by the time the cake is fully cool, the ganache will be the right spreading consistency.
If the ganache gets too thick while waiting, set the bowl over a pan of warm water for a minute and stir until it loosens back up.

Bake times by pan:

Pan Size	Time
8-inch round	28 to 32 mins
9-inch round	24 to 28 mins
8×8-inch square	30 to 35 mins

Check a few minutes early with a toothpick; ovens vary, and you want moist crumbs, not a clean skewer.

Keeping Leftover Cake Fresh

Refrigerate: wrap the cake tightly or store it in an airtight container for up to 4 days. The ganache will stay set and the cake remains moist straight from the fridge.
Serve Cold: most of the time I just slice it cold and let it sit on the plate for 5 minutes. It softens enough to taste rich without warming the ganache into a mess.

What To Serve With Belgian Chocolate Cake

A cloud of lightly sweetened whipped cream cuts through the richness and makes each bite feel airy. A scoop of vanilla ice cream does the same job with a little extra cold contrast, or you can keep it simple with a strong black coffee that plays against the dark chocolate.

Frequently Asked Questions

Can I use milk chocolate instead of dark?

You can, but the cake will be much sweeter and the chocolate flavor less pronounced. If you try it, reduce the sugar in the batter by 3 tablespoons and expect a softer, fudgier texture.

Why did my cake sink in the middle?

Usually the oven temperature was too high, or the cake was underbaked. An oven thermometer helps, and always test with a toothpick before pulling the cake out.

Can I freeze this cake?

Yes, wrap the unfrosted cake layer tightly in plastic wrap and freeze for up to 2 months. Thaw overnight in the fridge and pour the ganache on fresh for the best finish.

How can I make this gluten-free?

Substitute the all-purpose flour with a good 1:1 gluten-free baking flour blend. The crumb will be slightly more fragile but still moist and rich.