In brief
Dacquoise uses a nut-and-egg-white mixture for thin baked layers.
Useful to know
Dacquoise uses a nut-and-egg-white mixture for thin baked layers. King Arthur’s Chocolate Dacquoise adds cocoa and assembles the layers with hazelnut filling and whipped cream. [1]
These layers are not prepared like a butter cake. Their shape is set before baking, and drying belongs to the method. Fillings gradually change the crispness after assembly. If preparing ahead, account for that change rather than expecting an identical texture immediately and the next day. This is one chocolate version, not every possible dacquoise.
Sources
For further detail and to check the information: