No one knows what race they were, most probably "HUMAN" (yep Afro´s are also Human🙂) although when you consider the technology required to build the Pyramids, ie lift 200 Ton stones into place exactly, (when today there is only 1 crane in the world which can lift such mass, and don´t mention ramps, it´d have had to been 20 miles long). There could have at least been some help from other races, Aliens, Lizards🙂, Dimension travelers etc.
One interesting thing is that there was a grand total of NONE mummies, or deceased folk found in ANY Pyramid. So how the Egyptologists come about the idea that they were graves is beyond me.