The unofficial flavor of fall, pumpkin, has started to invade grocery store aisles yet again, according to a Nielsen report. In recent years, pumpkin flavoring has become increasingly popular, accounting for sales of $361 million in 2014 alone.  

Last fall, 37 percent of Americans purchased a pumpkin-flavored product, Nielsen reported, as a variety of nontraditional products flew off grocery store shelves. Pumpkin pie filling was the most popular pumpkin product in 2014, accounting for $135 million in sales. Pumpkin-flavored cream came next, with just under $48 million in sales. The other top products containing the popular flavoring in 2014, according to Nielsen, included coffee, baking mixes, baked bread, dog food, yogurt, ice cream, fresh desserts and milk.

While sales of the popular, autumn-flavored product have grown 79 percent since 2011, sales of fresh pumpkins have been declining. There were unit sale losses in 2011, 2013 and 2014, and an overall 8.6 million fewer were sold during that period. 

Major retailers have jumped on board, rolling out more and more pumpkin-flavored products as the weather gets chillier. Over the past few years, Starbucks has seen tremendous popularity with its Pumpkin Spice Latte product, and this year the coffeehouse changed its recipe to include real pumpkin and no caramel coloring, Fortune reported.

"This is a time all its own: Winter, spring, summer and pumpkin spice latte season," said a Starbucks spokeswoman, CNBC reported in 2013. "It's a testament to the pumpkin frenzy."

GettyImages-457649868 Retailers have been taking advantage of the high demand for pumpkin-flavored products; demand for pumpkins themselves, though, has been slowing. Photo: Getty Images

Ice cream retailer Carvel will also be offering several pumpkin-flavored treats beginning Sept. 21, including Pumpkin Sundae Dashers, pumpkin shakes, hand scooped pumpkin ice cream and pumpkin soft ice cream. Dunkin Donuts also announced it will be offering a variety of pumpkin-flavored products throughout the season, including lattes, coffees, donuts and muffins.

Bartenders also had pumpkin's popularity on their radar, and a number of mixologists last year invented pumpkin-permeated drinks, Slate reported. In Dallas, someone concocted a Cinderella’s Glass Slipper, made with pumpkin-infused applejack. A bar in Atlanta came up with a Great Rumkin, made with pumpkin spice-infused rum and pumpkin puree. And in Cleveland, tipplers raved about a pumpkin-based martini.

The big demand for pumpkin-flavored products will likely continue throughout the fall and through Christmas, Nielsen reported.