Wise men say only fools rush in, but Daniel Radcliffe can't help falling in love with a culinary curiosity favored by Elvis back in the day.

"It was absolutely fantastic," Radcliffe said of the delicacy known as Fool's Gold, which plays a key supporting role in his new movie, "What If." The romantic comedy with Zoe Kazan, Rafe Spall, Megan Park, Adam Driver and Mackenzie Davis opens in Atlanta on Friday.

Radcliffe plays lovelorn medical school dropout Wallace, who meets charming and lovely Chantry (Kazan) at a party. He's soured on romance since his last girlfriend stepped out on him, and she's involved with a guy although he seems more devoted to his career than to their relationship. So Wallace and Chantry decide to be just friends. No spoilers here but seriously, how hard is it to guess what happens?

You may find the story of Fool’s Gold more intriguing.

A then-teenage cook named Nick Andurlakis was working at a now-closed Denver restaurant called the Colorado Mine Company when Elvis was in town for a concert in the 1970s. When Andurlakis' buddies on the police force brought their famous visitor by for some post-show nourishment, the kitchen came up with the King-sized snack.

“Call me Elvis,” was his first marching order, Andurlakis recalled.

“Be sure to load up on the bacon,” was the second.

Elvis winged in on his private plane, the Lisa Marie, a few times after that initial visit, leaving Andurlakis with a few special gifts and enough anecdotes for a lifetime. Today the Fool's Gold, named with a mining theme in mind, is the specialty at Nick's Cafe, a memorabilia-laden breakfast and lunch spot in Golden, Colo. If you have no private plane to get you there, here's the recipe. It is listed on the cafe's website, foolsgoldloaf.com, along with the admonition, "This is no ordinary PB&J, folks. Eat at your own risk."

INGREDIENTS: 2 tablespoons of margarine, 1 loaf of French white bread, 1 pound of bacon slices, 1 jar of smooth peanut butter, 1 jar of grape jelly.

METHOD: “Preheat the oven to 350 (degrees). Spread the margarine generously all over all sides of the loaf. Place it on a baking sheet in the oven. Meanwhile, fry the bacon in a bit of oil until it is crisp and drain it thoroughly on paper towels. Remove the loaf from the oven when it is evenly browned, after approximately 15 minutes. Slice the loaf lengthwise and hollow out the interior, leaving as much bread along the walls as desired. Slather a thick layer of peanut butter in the cavity of the loaf and follow with another thick layer of grape jelly. Use lots of both.

“Arrange the bacon slices inside the cavity, or, if desired, layer the bacon slivers between the peanut butter and jelly. Close the loaf, slice and eat. Serves one if you’re Elvis. Serves 8-10 if you’re a regular person.”