Half Batch Baking on Instagram: "Here’s the science behind why cookies spread and how to prevent it. One of them is when a recipe calls for creaming butter and sugar together. This process adds air to the batter and increases the volume of the cookies. However, if the butter is too soft or melted, it can cause the cookies to spread more. Butter should between the temperature of 65-68F anything above 70F will be too warm. Melted butter has a lower viscosity, which allows it to flow more easily, r