Try to dry by liophilization (freeze drying).  To do that you have first to freeze the sample.

 Thank you but l need a method that utilizes an oven. The dried cells do not have to be viable

Christine:

The simplest way, depending on the quantity of Saccharomyces cerevisiae cells you are drying,  may be  to place the culture in a desiccator, with a desiccant like silica gel then just let it sit for a few days. The drying process can be assisted by applying a vacuum to the desiccator. 

https://www.sorbentsystems.com/desiccants_types.html

Steve

you need centrifuge to seperate the yeast from its growth media. It is operated at 2000-4000 rpm for 15-30 minutes. Then put the seperated yeast onto petri dish until it is full. Then put the petri dish in the oven at 70-80 degree C for 24 hours. Please excuse my poor english. Hope it works out for you.

Thank you so much. It does make sense