Hollywood producer Jack Giarraputo has listed 40 acres of scenic Malibu hillside for $31.5 million.

Mr. Giarraputo, a film veteran and co-founder of Adam Sandler’s Happy Madison Productions, has owned the empty land since 2003, according to property records. And he’s spent the past year and a half on a “passion project”—working out plans for a lavish contemporary equestrian property dubbed Sweetwater Ranch, said listing agent Tracy Tutor of Douglas Elliman. Variety first reported the new listing, which hit the market on Friday.

There’s never been any built structures on the property, but Mr. Giarraputo, in his 50s, has taken advantage of its picturesque location as an informal getaway to enjoy a nice bottle of wine or a cigar, said Ms. Tutor, who’s co-listing the home with fellow Douglas Elliman agent Gina Dickerson.

The property is located within the gated Serra retreat, on a winding road through the foothills. It feels isolated even though it’s only five minutes “to the front door of Nobu,” Ms. Tutor added, referring to the upscale sushi restaurant.

The 40 acres include about 14 acres of flat, buildable land, on which Los Angeles architect Standard has devised an elaborate compound inspired by the rustic-contemporary wineries found further north in California Wine Country. That means rich, barn-like materials, including dark-wood siding, limestone and a steel roof.

The architect’s plans include a 10,750-square-foot main mansion with seven bedrooms and thousands more square feet worth of covered loggias and rooftop terrace. The main house has a Zen-like reflection pool, gardens, a tennis court and one of two pools on the property, according to the architect’s renderings.

Giarraputo and his architects have dreamed up a larger 75-foot infinity pool by the guest house, which has its own patio, fire pit and sports bar designed with multiple TVs—a reflection of the seller’s personal taste.

“He designed every corner as if he were actually going to live in it himself,” said Ms. Tutor, who’s consulted Mr. Giarraputo throughout the process and on some occasions had to ask: “Is that for you or are we selling this?”

One suggestion in the design came from Ms. Tutor, who grew up in the area’s equestrian community. She saw acres of flat lawn as an ideal opportunity to raise horses.

“It’s an equestrian dream,” she said. The architect’s plans include an exceedingly modern barn in the same contemporary style as the main house, with three indoor and two outdoor stables, a tack room and wash walls. The property allows for acres of fenced pastures and an outdoor riding ring, images show.

“Horses never had it so good, it’s bananas,” she said, adding that the buyer could easily repurpose the planned stables into a detached office instead.

The proposed home is still in the approval process, something that’s expected to be completed by the end of this year. If the home doesn’t sell before then, Mr. Giarraputo will likely break ground and begin building the house early next year, according to the agent. He could not be reached for comment.