Complex sentence: In the late 1800s, candy makers started looking for a new process, and discovered the starch mogul system, in which trays of modified corn starch had a mold firmly pushed down in them to create cavities within the starch.
Split into simpler sentences: In the late 1800s, candy makers started looking for a new process, and discovered the starch mogul system. The way this system worked was that there were trays of modified corn starch, and each tray had a mold firmly pushed down in it to create cavities within the starch.