Butter Squares are a type of pastry made with a buttery shortbread crust and a sweet, creamy filling. They are often topped with a layer of chocolate or other sweet toppings. The term 'Butter Squares' is derived from the French phrase 'pâte à sucre, ' which translates to 'sugar dough.' The term 'PATS' is an acronym for 'Pastry and Sweet Treats, ' which is a category of desserts that includes Butter Squares.