This study aimed to develop a functional delivery system based on dark chocolate for double encapsulated extracts of four medicinal herbs, thereby creating a Nutraceutical Dark Chocolate (NDCh). Extracts of Crocus sativus L. (saffron), Rosa damascena (rosa), Melissa officinalis L. (balm), and Echium amoenum (borage) were encapsulated using a complexation-spray drying approach. The coacervates had a particle size ranging from 2.0 to 2.2 μm and a polydispersity index between 0.103 and 0.114. The first and second encapsulation efficiencies of spray-dried coacervates varied from 90.2 to 91.1% and 99.1–99.7%, respectively. NDCh samples, containing varying levels of microcapsules (500–885 mg per 33g of NDCh), exhibited an increase in Casson's plastic viscosity and yield stress compared to the control sample. The fortified NDCh samples demonstrated improved brittleness and superior melting properties, although their whitening index was lower than that of the control sample. Sensory analysis indicated that NDCh samples fortified with minimal amounts of balm and borage microcapsules, and maximal levels of saffron and rosa, received higher scores than even the control sample. In conclusion, the fortification of dark chocolate with microcapsules containing extracts of well-known sedative medicinal herbs could potentially introduce a new category of nutraceutical products with suitable technological and sensory properties. •A low-calorie, nutraceutical dark chocolate fortified with herbal extracts was formulated.•Extracts of Crocus sativus L., Rosa damascena, Melissa officinalis L., and Echium amoenum were used.•Complex coacervation-spray drying approaches were utilized for the double encapsulation of the extracts.•The textural and sensory properties of the designed chocolate were enhanced.•The visual characteristics of the samples, in terms of brightness and Chroma, were improved.