The first time I made chocolate clay, it turned too hard to work with. Today I gave it another try and the consistency is beautiful, soft and pliable however, as soon as I knead it it gets really greasy and all the fat seperates. Any ideas on what the problem might be? Thank you.

Do you have hot hands? Some people's hands are so warm that they can only work with modeling chocolate in small amounts, so that they can set one amount aside to cool a little while they knead a different amount.

Are you using the candy melts / corn syrup recipe? If you slightly warm the corn syrup, it helps.

Also, when you first make the mixture, as soon as it's cool enough to handle, knead out the oil over the sink. Divide the clay into smaller portions and knead each portion over the sink (it's messy) so that the excess oil can be worked out.

(edited to add that once you knead out the oil, then go ahead and let the clay rest until the next day, then use it as usual.)

HTH,
Deanna