Rich, Creamy Peanut Butter (250g / 1 cup): This is the foundational pillar of your dessert. You want a commercial-grade creamy peanut butter (like Jif or Skippy). Why? These brands contain hydrogenated vegetable oils that act as vital stabilizers. When you open the jar, it should smell intensely of roasted peanuts with a smooth, velvety, and homogeneous texture.Substitution: If you have a peanut allergy, sunflower seed butter or almond butter works beautifully. However, if using natural nut butters where the oil separates at the top, you must stir it vigorously until perfectly blended, otherwise, your dough will turn into a greasy puddle in the oven.Granulated White Sugar (200g / 1 cup): Sugar does much more than merely sweeten the dough; it is a critical structural element. The crystalline structure of white sugar cuts into the dense peanut butter, creating microscopic air pockets that help the dough rise slightly. It provides that classic, irresistible crisp edge that gives way to a chewy center.Substitution: For a deeper, more caramel-forward flavor profile with hints of molasses, substitute exactly half of the white sugar with tightly packed light brown sugar. For a refined sugar-free option, coconut sugar is an excellent 1:1 substitute, though it will yield a slightly darker, earthier final product.Large Egg (1, room temperature): In the complete absence of all-purpose flour and traditional gluten networks, the egg is your sole binding agent. The protein found in the egg white coagulates during the baking process to give the dough its physical structure, while the fat in the egg yolk provides a rich, tenderizing moisture that prevents the final product from becoming brittle.Substitution: For a completely vegan alternative, utilize a "flax egg." Vigorously whisk 1 tablespoon of finely ground flaxseed meal with 3 tablespoons of warm water and let it sit for 10 minutes until it develops a thick, gelatinous consistency.