Mocha & Hazelnut Brownies with Espresso Coffee

Step 1 – Roast the hazelnuts

First of all, it is essential to bring out the flavour of the hazelnuts.
Preheat the oven to 160°C (fan). Spread the whole hazelnuts on a baking tray lined with baking paper and roast for 10 to 12 minutes, until they release a warm, slightly caramelised aroma.

Once roasted, rub them between your hands or in a clean tea towel to remove their thin skins. This brings out a purer flavour and a more distinct crunch. Then set them aside.

Step 2 – Melt the chocolate and butter

In a small saucepan, gently melt the dark chocolate and butter over a bain-marie or over a very low heat. Stir with a spatula until smooth and glossy.

Once smooth, remove from the heat and immediately add the spoonful of hot espresso. This step is crucial: the coffee intensifies the chocolate notes and adds depth of flavour. The mixture should be fluid and free of lumps. Leave to cool until lukewarm.

Step 3 – Prepare the brownie batter

In a large mixing bowl, whisk the eggs, cane sugar, vanilla sugar and pinch of salt for 2 to 3 minutes, until the mixture becomes slightly paler and frothy.
This step incorporates air, ensuring a melt-in-the-mouth texture without heaviness.

Next, pour the melted chocolate (lukewarm, not hot) into the egg and sugar mixture, then whisk until the batter is smooth and satiny.

Add the sifted flour and cocoa, then fold in gently with a spatula or flexible spatula. The secret is to avoid overworking the batter, to preserve the brownie's characteristic density.

Finally, add the roughly chopped roasted hazelnuts and, if you wish, the chocolate chips for an even more melt-in-the-mouth texture.

Step 4 – Bake the brownie to perfection

Preheat the oven to 170°C (conventional).
Butter and flour a square baking tin measuring approximately 20 x 20 cm, or line it with baking paper.

Pour the batter into the tin, smooth the surface and scatter a few whole or chopped hazelnuts on top for a rustic, crunchy finish.

Bake for 22 to 25 minutes. The baking time is crucial: an overbaked brownie becomes dry, while a perfect brownie should still have a slight wobble in the centre. To check, insert a knife blade: it should come out with a few moist crumbs, but no liquid batter.

Leave to cool completely in the tin before cutting. This resting time allows the texture to set and become softer.

Step 5 – Rest and slice

Once at room temperature, place the brownie in the fridge for at least 1 hour. This optional but recommended step makes the cake denser and richer.
Then cut into neat squares using a knife dipped in hot water (and wiped clean after each cut).

Dust lightly with unsweetened cocoa powder and arrange a few chocolate-coated coffee beans on top for an elegant touch.

Step 6 – Serving & pairings

The mocha and hazelnut brownie reveals its full complexity on the palate after resting for a few hours. Serve it at room temperature to release the coffee and cocoa aromas.

Coffee pairings:

• A full-bodied espresso (Ethiopian Arabica or an Italian blend) will bring out the brownie's chocolatey depth.
• For a milder pairing, a latte or cappuccino will soften the intensity of the cocoa with its creaminess.
• Filter coffee lovers will appreciate the contrast between the coffee's floral bitterness and the brownie's dense texture.

Dessert pairings:

• A scoop of vanilla or praline ice cream melting on top for a hot-and-cold dessert.
• Coffee custard or a salted butter caramel sauce for extra indulgence.
• For a festive version: a drizzle of chocolate ganache and a few pieces of caramelised hazelnut.

Chef's tips

1. Fresh coffee is essential: use a real, freshly brewed espresso, not dissolved instant coffee. It will add an incomparable richness of flavour.
2. Quality chocolate: choose dark chocolate with a cocoa content between 70% and 75%, neither too bitter nor too sweet.
3. Control the baking time: for a gooey centre, reduce the baking time by 2 to 3 minutes; for a firmer brownie, add 2 minutes.
4. Resting is essential: the longer the brownie rests, the denser, softer and more flavoursome it becomes.
5. Gluten-free version: replace the flour with 60 g ground almonds or rice flour.
6. Vegan version: replace the butter with plant-based margarine and the eggs with a mixture of apple purée and soaked ground flaxseeds.

Sensory profile

From the first bite, the dense texture gives way to release a cascade of flavours: the caramelised sweetness of cane sugar, the earthy intensity of cocoa and a subtle hint of coffee bitterness that lingers on the palate. The hazelnuts add a delicate, toasted crunch, contrasting with the melt-in-the-mouth chocolate centre.

The coffee aroma stays in the background without dominating: it gives structure, balances and prolongs the chocolate note, like a bass chord in an indulgent symphony.

In summary: the elegance of coffee in a chocolate square

These mocha & hazelnut brownies with espresso coffee are much more than a dessert. They are little squares of energy, perfect for a refined coffee break or to round off dinner with friends.
Their secret lies in simple ingredients, precise technique and respect for coffee as a fine ingredient.

Each bite brings together the velvety texture of chocolate and the aromatic intensity of coffee — a perfect balance between sweetness and intensity.