## 1 Introduction  
Bakery products include items such as cakes or cookies, and they are consumed daily in large quantities. The main issue is that these types of ultra-processed foods are filled with saturated fats, refined flours, and sugars [1]. One of the most popular products worldwide is chocolate brownies, which are made from butter, sugar, flour, chocolate, and eggs. Specifically, much of the brownie formulation consists of butter, which is a saturated fatty acid (SFA). In recent years, the baking industry has increasingly embraced healthier and more sustainable ingredients, with a particular interest in replacing butter with vegetable oils, as they are rich in unsaturated fats [2]. Studies have shown that these oils can enhance the lipid profile of baked goods by lowering the saturated fat content, which is linked to LDL cholesterol and cardiovascular risk [3]. This shift aligns with the growing demand for functional foods, a sector experiencing immense growth with annual growth rates between 8% and 14%, and global market estimates of approximately USD 167 billion [4]. As the incidence of obesity, type 2 diabetes, and cardiovascular diseases rises, food industries around the world produce foods whose packaging contains unattractive labels due to high levels of salt, sugar, and fats, especially saturated fats [5]. The dietary intake of saturated fats, such as butter, has been associated with an increased risk of cardiovascular diseases as they tend to raise low-density lipoprotein cholesterol. Randomized clinical trials testing the effects of reducing saturated fats on cardiovascular risk have generally replaced saturated fats with polyunsaturated fats, monounsaturated fats, or carbohydrates [6]. Despite the well-documented risk of excessive saturated fat consumption, these fats remain prevalent in many diets due to the wide availability of foods rich in them and a lack of public awareness about their dangers. According to [7], the main cardiovascular diseases (CVDs) arise due to excessive consumption of fats, especially saturated fats. The consumption of monounsaturated fatty acids found in vegetable oils and Omega-3, present not only in animal-derived foods like salmon or tuna but also in plant-based sources such as nuts, helps to prevent these types of diseases by reducing cholesterol levels, triglycerides, and blood pressure. Moreover, the consumption of products rich in polyphenols, vitamins, and minerals, which are also found in nuts, and which have antioxidant, anti-inflammatory, anticancerogenic, and cardiovascular protective effects, has been shown in epidemiological studies to have the potential to reduce the risk of cardiovascular diseases [8]. Saturated fats are used in baked goods because they contribute to mouthfeel, tenderness, structure, moisture, flavor, texture, and overall acceptability [9]. Additionally, the role of fats is to trap air in the dough during mixing, which provides structure for the leavening gases. They also affect the final product's volume and interfere with the protein matrix, adding lubricity to the texture by coating starch and protein particles [10]. Nuts are a potential source of unsaturated fatty acids, protein, dietary fiber, minerals such as potassium and magnesium, vitamin E, folate, and other bioactive compounds such as phenols and phytosterols [11]. Many of the nutritional components of nuts have been studied due to their multiple health benefits [12]. Pistachios have a high content of unsaturated and monounsaturated fats; specifically, they are rich in linoleic acid (13.1 g/100 g) and oleic acid (23.9 g/100 g). This oil can be used by the food industry as a continent or a substitute for saturated fats, due to its flavor, aroma, and color, creating new culinaryperspectives. It can also be used in the cosmetic and pharmaceutical industries due to its emollient properties and vitamin content [13]. Walnut is very rich in monounsaturated fatty acids. It is a perfect source of Omega-3 and arachidonic acid.