The demand for plant-based alternatives has grown significantly in recent years, driven by environmental, animal welfare, and health concerns. This study focused on oat-based frozen desserts, with dairy-based ice cream included as a reference, examining sensory perception and overall pleasantness among children (8-16 years) and adults (n = 210; 105 each) in Estonia and Latvia. Exploring how different groups perceive these products would indicate what to focus on in product development. While all samples were rated as generally pleasant, flavour emerged as the primary driver of overall pleasantness. Dairy-based ice cream consistently received the highest ratings across all groups, linked to sensory qualities like "vanilla," "sweet," "buttery," "milky," and "natural", as well as its "fattier" and "creamier" texture, likely enhanced by milk fat. Among oat-based samples, the least pleasant sample exhibited off-notes, likely caused by added flavouring rather than plant-based ingredients, as "vegetal" nuances were consistent across all oat-based products. Children were less attentive to "off-flavour" and "vegetal" flavours, possibly due to children's simpler sensory expectations. Similar tendency was shown with Latvians, which could be related to lower ice cream consumption in Latvia compared to Estonia, leading to less defined expectations. These findings highlight the need to improve the sensory attributes of oat-based frozen desserts, particularly through flavour and possibly texture refinement. Enhancing these characteristics is essential to increasing consumer acceptance, especially among those more familiar with dairy products. Aligning these improvements with targeted marketing strategies could further boost the acceptance and consumption of plant-based frozen desserts.