However, you could use some of these options:
* A batch of scones
* A plate of scones
* A basket of scones
* A spread of scones
* A selection of scones
You could also be creative and use something like:
* A cloud of scones (if they are light and fluffy)
* A symphony of scones (if they are diverse in flavour)
Ultimately, the best collective noun depends on the context and what you want to convey.