Now, if you're feeling fancy, you could try using icing sugar as a substitute. Just be warned: it's super fine, so use it sparingly or you'll end up with a batch of baked goods that are way too sweet. And don't even get me started on the mess it can make - it's like a snowy explosion in your kitchen!
But what about brown sugar, you ask? Well, it's a bit of a wildcard, but it can work in some recipes. Just keep in mind that it has a richer, more caramelly flavor than caster sugar, so it might change the overall taste of your baked goods. And if you're using it in a recipe that requires a lot of sugar, you might end up with a batch that's a bit too moist.
Now, I know what you're thinking: what about honey or maple syrup? Can't I just use those instead of sugar? Well, not exactly - while they're both delicious, they have a stronger flavor than sugar and can make your baked goods way too sweet. Plus, they have a higher water content, which can affect the texture of your final product.
What Is Caster Sugar? What Can I Use Instead Of Caster Sugar? – KimEcopak
