Depends on the recipe. In some cases the larger grains of the sugar will ruin the texture and cause the mixture to not mix correctly, in other cases nothing will happen. If you are making a glaze out of confectioner's sugar and water, then regular sugar will not work.
Caster sugar has finer granules than regular (or "granulated") sugar. For cupcakes, you should be able to use regular sugar instead of castor without any detriment to the final product.
Yes. However, if you use baking soda instead of powder, you'll need to include some acid. A teaspoon of lemon juice or using buttermilk instead of regular milk will work.
Gun powder can be used as a propellant rather than powdered sugar and KNO3 depending on the application. Both are explosive, however gun powder is designed to ignite at much higher speeds.
You can use regular icing, candies, chocolates, coconut, nuts, melted sugar, or other forms of decorations instead, too.
Yes, you can use cane sugar instead of white sugar in this recipe.
rwgular sugar is granulated sugar. the other kind is confectioner's sugar, or powdered sugar
Follow the recipe for the amount of baking powder to use whether your using regular flour or cake flour. Neither of them have baking powder, unless it is "self rising" which means leavening is included.
I have tried it and dosent make much of a diffrence!
Talcum powder
You can use fresh onions, garlic powder, or shallots as alternatives to onion powder in your recipe.
You can indeed, the cake may be marginally denser as a result.
Not really. Nescafe is ground coffee powder, not cocoa powder.