Back in 1976, Klein created Jelly Belly jelly beans, a product that revolutionized the candy industry by putting a gourmet spin on the lowly jelly bean.
"Before me, jelly beans were just eaten at Easter," Klein told AOL News. "They all tasted the same. I came up with the idea of having them taste in different flavors and using high-quality ingredients."
However, Klein was bought out in 1980 by Herman Goelitz, whom he had hired to manufacture the candy.
Klein made the decision to sell for a variety of reasons and soon regretted it.
"I would have liked to see what I could to take Jelly Belly to the next level," he admitted.
Klein's company, Can You Imagine That Confections, did fair to middling, with most of the success coming from Sandy Candy, a powdered candy version of sand art that was invented by his daughter, Roxanne, when she was 15.
The last 30 years haven't great for him, especially because he's been written out of the Jelly Belly corporate history.
"If you go to the Jelly Belly website, I am completely written out of it," Klein said. "They just say a 'candy distributor in Los Angeles,' but not my name. I am mentioned in Wikipedia as the creator, but I had to put that in myself and, of course, someone can try and take it out."
But Klein may be getting his "just desserts" at last. He is the subject of a new documentary, "Candyman: The David Klein Story," which will be reaired on the Documentary Channel on Jan. 11.
"People who've seen it are amazed," he said. "They say I'm the best-kept secret in the candy business."
That could change. Klein is convinced his latest creation may rival Jelly Belly.
It's a 2.5-pound anatomically correct gummy heart that he calls, appropriately enough, "The World's Largest Gummy Heart." It sells for a whopping $30, and, Klein points out, oozes candy blood in 11 spots.
Klein came up with the product a little while ago and is rushing it to market without doing anything corporate like, say, test marketing.
"I don't do any test marketing," he said. "By the time you do it, 10 competitors will find out. There's no legal protection if you come out with a candy. Besides, this way, I can get a product out in three weeks.
"Besides, what's more perfect than a heart on Valentine's Day?" he asked.
Klein also plans a gummy foot that comes with a gangrenous toe (candy, of course), candy barf and a gummy bleeding nose.
Surprisingly, he says the key to these products is good taste.
"When you have a novelty product, it's important that it taste good, because, otherwise, no one will buy it more than once," Klein said.
That includes one of his other products, "Formula Pee," which is a lemon-flavored candy that comes in a urine-specimen bottle.
Although Klein is proud of products such as the candy-blood-oozing gummy heart, he says Jelly Belly suffers from a lack of good taste.
"I am against those Harry Potter flavors like 'booger' or 'snot,' " he said. "I created a gourmet product. When people find out I created Jelly Belly, the first thing they ask if I created those. No!"