Hazelnut Dacquoise with Coffee French Buttercream
A hazelnut dacquoise is a French meringue baked with ground nuts until it’s crisp on the outside and just barely chewy in the centre. The coffee French buttercream is built on a pâte à bombe base, which means hot sugar syrup poured into egg yolks before the butter goes in. It’s richer, silkier, and more stable than a standard buttercream. Worth the thermometer.
Hazelnut Dacquoise with Coffee French Buttercream
A hazelnut meringue layered with silky coffee French buttercream. Technically precise, deeply satisfying, and worth every step.
Equipment
- 1 Stand mixer with balloon whisk attachment
- 1 Food processor
- 1 Small saucepan
- 2 30cm x 40cm baking trays
- 1 Offset spatula
- 2 Cooling rack
- 1 Piping bag
- 1 Thermometer
Ingredients
Coffee Mixture
- 20 g instant espresso powder
- 30 g boiling water
- 12 g vanilla extract
Hazelnut Dacquoise
- 400 g toasted hazelnuts skins removed
- 70 g icing sugar
- 60 g cornflour
- 400 g egg whites room temperature
- 350 g caster sugar
- 2 g fine salt
Coffee French Buttercream
- 14 egg yolks
- 400 g caster sugar
- 120 g water
- 750 g unsalted butter cool but pliable, cubed
- 2 g fine salt
To Finish
- 40 g toasted hazelnuts finely chopped
- cocoa powder for dusting
Instructions
Coffee Mixture
- Combine espresso powder and boiling water in a small bowl and stir until fully dissolved.
- Stir in vanilla extract and set aside to cool fully before using.
Hazelnut Dacquoise
- Preheat the oven to 160°C fan for 20 minutes.
- Line two 30cm x 40cm trays with baking paper. Make incisions from the corner to the size of the tray to allow the paper to fold neatly.
- Add hazelnuts, icing sugar and cornflour to a food processor.
- Pulse to a coarse sandy meal. Do not let it turn oily.
- Add egg whites and salt to a clean bowl.
- Whisk to soft peaks.
- Gradually add caster sugar one tablespoon at a time every 30–60 seconds and whisk to a glossy medium firm meringue.
- Fold in the hazelnut mixture in 3–4 additions until just combined. Do not deflate the meringue.
- Spread onto the tray about 2cm thick. Level the surface with an offset spatula.
- Bake for 24 to 30 minutes until lightly golden, dry on top, set in the centre, and lightly springy.
- Remove from the oven and cool on a cooling rack.
- Turn out, peel away the paper, and trim the edges.
- Cut into even squares or rectangles. Keep half for the bases and half for the tops.
Coffee French Buttercream
- Add egg yolks to the bowl of a stand mixer fitted with the balloon whisk.
- Whisk on medium speed for 2 to 3 minutes until slightly thickened and lighter in colour.
- Add caster sugar and water to a small saucepan.
- Heat over medium heat, stirring only until dissolved. Stop stirring and cook to 118°C.
- With the mixer on medium speed, pour the hot syrup into the yolks in a thin steady stream down the side of the bowl.
- Increase to medium high speed and whisk until thick, pale and glossy. This is the pâte à bombe. Keep whisking until the bowl is completely cool.
- Reduce to medium speed and add the butter a few cubes at a time.
- Keep mixing until smooth. If it looks split or curdled, keep going — it will come together.
- Add the cooled coffee mixture and salt. Beat until smooth, silky and pipeable. If too soft, chill briefly then beat again.
Assembly
- Transfer the buttercream to a piping bag.
- Pipe onto the dacquoise pieces in neat dots.
- Top with the remaining dacquoise pieces and press very lightly to settle.
- Refrigerate for 15 to 30 minutes until the buttercream is firm.
- Pipe a small rosette on top of each portion. Finish with chopped hazelnuts or a light dusting of cocoa if using.
Notes
Storage
These can be stored in the fridge for a few days. Take them out 10 minutes before serving to soften the buttercream.Key pitfalls:
- Make the coffee mixture first so it cools fully before use
- Do not overprocess the hazelnuts — you want a coarse sandy meal, not a paste
- Bake until the centre is set, not just coloured on top
- The pâte à bombe must be completely cool before you add the butter
- Butter should be cool but pliable — it should indent when pressed but not look greasy
- Chill after assembly for clean portions
