Ingredients :

• Cocoa powder — It does two things at once: flavors and thickens. Don’t swap it for melted chocolate—the final texture won’t be the same. Dutch-processed or natural, both work here since there are no leavening agents in the recipe.
• Peanut butter — Go for classic commercial peanut butter, not the natural version that separates into two layers in the jar. Natural can make the texture grainy and unstable. If you only have natural, stir it thoroughly before measuring, and it should hold up.
• Oats — Instant oats (quick oats) provide better cohesion—the cookies hold together more easily. Rolled oats work too, but the result will be rustier and slightly more fragile. Both are good; it’s just a matter of how they feel in your hand.
• Sugar — Ordinary granulated white sugar, in the exact amount specified. No brown sugar, no reductions. This is one of those rare recipes where sugar proportions truly impact the set: too little, and the cookies stay soft and sticky.