Given the increasing need to reduce food losses and implement circular economy strategies, plant-based processing byproducts represent a promising source of functional ingredients. The aim of this study was to comprehensively assess the potential of pumpkin peels as a raw material for enriching cereal products, as a value-added ingredient for wheat pasta, and to analyze their nutritional and technological properties. Pumpkin peels were dried, ground, and thoroughly analyzed for chemical composition, bioactive compound content, and functional properties. Model pastas were developed with a 5–15% addition of pumpkin peel powder and assessed for their chemical composition, cooking quality, rheological behavior, antioxidant properties, starch digestibility, texture, oxidative stability, and in vitro prebiotic potential, as well as their health-promoting potential. The results demonstrated that pumpkin peel powder was a rich source of dietary fiber, polyphenols, and carotenoids, which translates into high antioxidant activity. Enriching the pasta with this raw material significantly increased the content of bioactive components and fiber, while having a moderate impact on technological properties. The most beneficial effects were achieved with a 10–15% addition, although higher levels may affect texture and cooking parameters. Pumpkin peels can therefore be a valuable ingredient in functional foods, supporting waste valorization and circular bioeconomy strategies.