hi everyone, do you have any idea how many cups of batter needed to make a 1 kilogram cake?

The weight of cake batter varies depending upon the recipe.

Why do you need a 1kg cake?

1 kg of fruit cake is a lot smaller than 1 kg of sponge cake
Also the topping and or frosting/ filling adds to the weight

Much easier to get the client to accept serving amounts

If you make fruit cake, it is a lot more filling than a sponge cake, of the later you can eat much bigger slices. Whipped cream does not weigh as much as fondant or frosting and you need less weight of whipped cream to cover a cake of the same size, than you would fondant or frosting