no jabba, obviously there are not molds
generally they place little flags where the tops of all the moguls should be, and a bunch of skiers ski down the course turning at the flags.
moguls can also be built by a snow cat by making a set of rollers that are spaced out the length of one snow cat. the cat then travels up the hill pushing rollers half way up, making a checkerboard of rollers that are 1/2 cat length apart, 1 cat width wide. then a SHIT PILE of man made snow is blown on this rubble field created by the groomer, and it ends up looking like an egg crate mattress. the mattress is then skied in til it looks like proper moguls