A relaxation brownie that contains melatonin to calm down nerves and act as a sleep aid is at the center of a storm in the US following the hospitalization of a toddler.

The chocolate-covered brownie snacks fall at the other end of a spectrum currently dominated by hundreds of energizing drinks. Instead of offering high-octane bolts of energy via caffeine, Lazy Cakes contain 8 mg of melatonin, a naturally occurring compound the body produces to help regulate sleep cycles. A typical dose of melatonin for adults in the US is between 1 to 3 mg.

Sold as a dietary supplement, the company says the product is targeted towards adults to help them relax and sleep safely.

But reports that a 2-year-old toddler was rushed to hospital after biting into the brownie and falling into a deep sleep have prompted the Arizona Department of Health to issue a mass recall Thursday, saying the product poses a potential health risk to consumers, especially young children, reports local station Ozarskfirst.com. The department also says melatonin hasn't been approved for use in general food products and advises consumers to throw out the product.

Parents and local officials in two Massachusetts towns have also lashed out against the company's choice of packaging, calling the product a child safety issue: on the wrapper is a cartoon character called Larry Lazy Cakes, a mascot that's unmistakably targeted towards children, critics said.

Meanwhile, the company's Facebook page has garnered more than 26,000 ‘likes' with several members discussing Lazy Cake spotting around the country.

Junk food marketing campaigns targeting children have become a major issue in the US, with a growing chorus of parents and health professionals blaming the industry for the country's childhood obesity epidemic. On Wednesday, for example, hundreds of doctors rallied together asking McDonald's to retire Ronald McDonald and Happy Meals.

The interest in Lazy Cakes, which launched late last year, also signals a drastic shift away from the popularity of energizing drinks into a full-on reversal in the opposite direction: relaxation foods.

A carbonated beverage, Drank contains the same ingredients found in Lazy Cakes - melatonin, rose hips, valerian root -  to help consumers relax.

Other relaxation dessert snacks include Lulla Pies and Kush Cakes.

A three-pack of Lazy Cakes costs $9.99 and is sold online in the US only.