Background: Non-conventional protein sources, such as edible insects and microalgae, are gaining popularity due to their high nutritional value and environmental benefits. The presented study aimed to examine the effect of a 4% addition of house cricket and spirulina powders on selected properties of muffins. The effects of non-conventional additives on color, textural properties, nutritional value, amino acid composition, and mineral content were determined. Methods: Antioxidant activity was evaluated against DPPH· and ABTS·+, and total phenolic content (TPC) and in vitro predicted glycemic index (GI) were examined. Sensory properties were evaluated using a nine-point hedonic scale and a consumer study. Results: The results showed that the additions of house cricket and spirulina significantly changed the color parameters of the muffins (ΔE 8.28 and 39.17, respectively) and affected their hardness, cohesiveness, gumminess, and chewiness. Nutritional value was improved, mainly due to an increase in protein content (up to 6% more). Overall, the amino acid profile of the muffins was improved, with a higher presence of all essential amino acids. The enriched muffins had a higher content of selected minerals, including iron, calcium, magnesium, potassium, and zinc, and exhibited higher TPC and antioxidant activity along with a lower in vitro predicted glycemic index. In the consumer evaluation, the spirulina muffins scored highest in texture (8.07 ± 1.04), while cricket muffins received the lowest ratings for color (6.60 ± 1.63), aroma (6.36 ± 2.04), and overall impression (7.03 ± 1.38). Taste did not differ significantly among all muffins. Conclusions: The results suggest that muffins can be made using edible insects and microalgae to enhance their nutritional value while maintaining an acceptable taste.