Hi Sterling,

In SpaceClaim, on the Design tab, use the Combine tool. Select the block as the Target then select the sphere as the cutter object. It will subtract the two and leave you with a solid of interference and the block will have a spherical cavity in it.  You can delete the solid of interference if you don't want it.

You can create a surface from the cavity face by simply selecting the face and type Ctrl-C, Ctrl-V to copy/paste the face and create a surface.