President Barack Obama eats pecan pie in the Oval Office Private Dining Room, Feb. 18, 2016. (Official White House Photo by Pete Souza)

President Obama celebrated “Pi Day” (it falls on March 14, or 3/14, like the mathematical constant) like many Americans: with a slice of pie.

Unlike most other pastries being devoured by math nerds across the land, the president’s had some significance baked into the recipe.

The White House Facebook page on Monday featured a picture of Obama grinning and holding a forkful that hails from the Red Truck Bakery in Marshall, Va. Along with the photo, Obama posted a letter that bakery owner Brian Noyes had written him in January.

In the letter, Noyes described leaving his job as the art director of Smithsonian magazine (previously, he was the art director of The Washington Post) to start the small company in rural Virginia — just as the recession was kicking in. Investors fled and the economy faltered, but Noyes said he felt obligated to the employees he had hired and the farmers who had added special crops to supply him. “I followed the news closely, listening to you and your team work to keep the economy afloat and I put my faith in your plans and positive attitude,” he wrote.

Noyes described for the president his flourishing enterprise today: He’s up to 47 employees and has just opened a second location. “I’m glad we hung on,” he wrote, and he invited the president to “Come in and see how things have worked out.”

Noyes says he never dreamed he would get more than a form-letter response. So he was surprised when an employee told him a few weeks after sending the letter that a White House staffer had stopped by the bakery on the Friday before Valentine’s Day weekend with a hand-delivered letter. From the president. “I was like, ‘What?'” Noyes recalled.

And it wasn’t even a low-level gofer who’d couriered the missive. It was speechwriter Cody Keenan, who told Noyes later that the personal touch was unusual but that he had happened to be passing by, en route to a weekend with his fiancee at the Inn at Little Washington. Keenan reported that he’d picked up a pecan pie for the president, a moonshine pie for the White House correspondence team and a meatloaf sandwich for himself.

And that’s when Noyes said something that he now realizes was pretty gutsy. “I told him that the pecan pie was perfectly adequate, but what the president really needed to try was the sweet potato bourbon pecan pie,” a newer addition to his shop’s lineup that is getting customer raves. “I can’t believe I said that. That was kind of brazen.”

So he delivered the substitute confection — along with a few other goodies, including another meatloaf sandwich — to Keenan’s apartment.

Apparently, the extra effort paid off, and the president had the White House photographer snap a picture of himself sampling the decadent goods. “I like pie,” Obama wrote in the Facebook post accompanying the snap. “That’s not a state secret. I like comeback stories, too. So in celebration of Pi Day, I wanted to share a great letter about both.”

Noyes credits the administration with helping to turn around the economy — and now he can draw a direct line between the president’s actions and his company’s bottom line. Just hours after the White House’s post went up, Noyes’s phone was bringing him good news. “I get notices when there are Internet sales, and it’s been like, ding, ding, ding,” he said.