Todd Wilbur's second career started with a chain letter — one of those "send this to five friends" deals that claimed to contain the secret recipe for Mrs. Fields' famous chocolate chip cookies.

The recipe, and the attached story (something about an old woman being suckered into spending $250 for the instructions), were bogus, but they got Wilbur thinking. What if you could come up with the "secret" recipe for popular dishes made by chains like McDonald's, Applebee's and KFC? How hard could it really be?

Wilbur started with the Mrs. Fields hoax, eventually coming up with a recipe that was a variation on the Nestlé Tollhouse classic and tasted remarkably close to Debbie Fields' moneymaker. Then he moved on to more savory exploits. For his second recipe, he reverse-engineered the Big Mac. That special sauce? It's basically Thousand Island dressing.

A former TV news reporter, Wilbur now works full-time cloning recipes for his cookbooks, which are for sale on QVC and have been featured on Oprah and Live with Regis and Kelly. He's not a chef or an innovator; he's a casual-dining cloner, and success means tasting just like the real thing.

"I want it to be exact," Wilbur says as he gets to work on recreating a batch of cous cous salad from the Houston's chain of restaurants. "I don't want to make it better; I don't want to make it worse. I don't want to make it less fat. I don't want to do anything to it except exactly duplicate it."

So far, the Summerlin resident has exactly duplicated enough recipes for nine cookbooks. His 10th, 17 recipes shy of completion, should be out in September. The book will be called Top Secret Restaurant Recipes 3. "Alternate title: The Greatest Cookbook Ever Written," Wilbur jokes.

Since publishing his first in 1993, Wilbur has sold close to 5 million copies of his cookbooks, all of which tackle well-known recipes from fast food or casual dining chains and break them down for cooks to re-create at home. His 1,000th recipe — the one most requested by visitors to his website — was Olive Garden's chicken and gnocchi soup, or as Wilbur describes it, "really good shit." Flipping through the pages of his books is like looking at a greatest-hits menu from chain restaurants: Buffalo Wild Wings' Caribbean jerk sauce, the Cheesecake Factory's Bang-Bang Chicken and Shrimp, Chili's lettuce wraps, KFC's biscuits.

Of course, some recipes take longer to crack than others. Recently, Wilbur's been struggling with Mastro's butter cake. "I know it's tons of butter and cake. I think it's more butter than cake," he muses. After attempting it about 16 times — and taste-testing his handiwork — Wilbur's stomach couldn't take another trial, but he swears the recipe will be in his next book.

And Wilbur has all kinds of tricks for figuring out what goes into the dishes that people crave. Sometimes he asks for a seat at the bar or near the kitchen, so he can watch how desserts or dishes are assembled. Other times he claims to be a strict vegetarian or vegan, so he can find out if a dish contains chicken broth or animal fat. When Oprah Winfrey challenged him to create the Jack Daniel's grill glaze from TGIFriday's before appearing on her show, Wilbur faked an allergy so the restaurant would give him a list of the ingredients.

There's something detective-like about cloning a recipe. You might even imagine a mega-chain getting its feathers ruffled by some guy out in Las Vegas telling everyone what's really in their special sauce. But none of the restaurants Wilbur's mimicked has paid much attention to his exploits, except KFC, which sponsored one of Wilbur's book tours.

Regardless, he keeps playing investigator, hunting for clues and putting the pieces together until he's completed a culinary puzzle that tastes fresh off the line.

"I found this niche that made [cooking] fun and different and a game. And that's what I like — games," Wilbur says. "I haven't gone through Dumpsters yet, but I'm not above that."