The aim of this study was to investigate the impact of replacing a portion of maize flour with hazelnut press-cake flour, added in amounts of 20, 40, and 60%, on the quality of gluten-free biscuits. In addition to the influence of adding hazelnut press-cake flour, the study also examined the effect of hazelnut oil sediment remaining after cold pressing and the impact of hazelnut oil used in this study as a fat source instead of shortening. Through the analysis of parameters such as water content, water activity, dimensions, colour, texture, and sensory properties, the influence of adding these components was examined. The results showed that adding hazelnut press-cake flour led to a reduction in water content and activity in gluten-free biscuits. The width of biscuits was not significantly altered by the addition of hazelnut press-cake flour, but the height was reduced, while the spread factor increased, which can be explained by the hydrophobic properties of the oil creating a barrier against water penetration into the dough. The hardness of the gluten-free biscuits was higher in samples with hazelnut oil compared to those with hazelnut oil sediment, likely due to the lower ability of liquid oils to retain gases during baking compared to solid fats. The addition of hazelnut press-cake flour significantly influenced the colour change of the biscuits, which were noticeably darker than those made with 100% maize flour. Samples produced with hazelnut oil and 60% hazelnut press-cake flour received the highest sensory scores, while samples with hazelnut oil sediment were rated significantly lower.