Oyster mushroom (Pleurotus ostreatus), nopal (Opuntia ficus-indica) and amaranth (Amaranthus spp.) are pre-hispanic foods widely consumed in Mexico. However, there are no standard products developed with these ingredients as functional cookies. This study evaluated the impact of partial replacement (50%) of whole-wheat flour (WWF) with three formulations of P. ostreatus, nopal and amaranth flours (POF, NF and AF, respectively) in the nutritional/antioxidant properties of fortified cookies. The proportion of flours´ ingredients (WWF:AF:NF:POF) were 100% WWF (traditional cookies), 50:35:10:5 (formulation 1), 50:30:15:5 (formulation 2) and 50:40:5:5 (formulation 3). Proximal composition, phenolic/flavonoid contents, and ABTS+ scavenging activity were determined in flours and cookies. POF, NF and AF possess a high nutritional value comprising polyphenols/flavonoids and a significant antioxidant potential. Total protein, ashes and flavonoids were higher in fortified cookies than controls. Cookies prepared with Formulation 2 -highest nopal level- contained 5.29% of dietary fiber and 5-times higher polyphenol content than control cookies. The ABTS+ scavenging ability was similar in the three enriched cookies (87.73-89.58%) but higher than traditional cookies (75.60%). Applicability of POF/NF/AF for replacing up to 50% of WWF in production of functional cookies was demonstrated. The research promotes renewable local bioresouces for a sustainable agri-food chain, especially edible mushrooms.