Biscuits Turned Out Doughy?

Too much liquid and/or too much grease/oil. Also, with biscuits you do not mix them up very long, just enough to mix the ingredients together.

Sounds like you didn't cook them long enough. Try a lower heat and longer baking time.

This happened to me last week when I had my son and his wife over for dinner. They were both looking forward to my biscuits. Alas twas not to be! Later, I looked on the bottom of my baking powder can and saw that it had expired four years ago!