Can you replace caster sugar with icing in baking cookies?

You cannot directly replace caster sugar with icing sugar (also known as powdered sugar) in baking cookies. Here's why:

* Texture: Icing sugar is much finer than caster sugar. Using it directly will result in cookies that are too dense and crumbly. The texture won't be the same.

* Sweetness: Icing sugar is more intensely sweet than caster sugar. Substituting it directly will make your cookies overly sweet.

* Moisture: Icing sugar has a higher moisture content than caster sugar. This can lead to cookies that spread too much while baking and have a slightly sticky texture.

Instead of direct replacement:

* Use a combination of icing sugar and cornstarch: To achieve a similar texture and sweetness, you can mix icing sugar with a small amount of cornstarch (about 1 teaspoon per cup of icing sugar). The cornstarch helps absorb moisture and prevent excessive spreading.

* Use granulated sugar: If you want to maintain the texture of your cookies, use granulated sugar instead of caster sugar. Granulated sugar is a more common substitute for caster sugar in most recipes.

* Adjust the amount of sweetener: If you absolutely must use icing sugar, start with a smaller quantity than you would with caster sugar and adjust based on your taste preference.

Remember:

* Always test your recipes before making a large batch.

* Adjust the amount of liquid in the recipe if you are substituting with a different type of sugar.

* Consider the type of cookie you are making. Some recipes, like gingerbread, call for a specific type of sugar and substituting it can affect the final outcome.