Spencer Warren has a 10-by-10 storage facility chock-full of Santa Claus heads.

The holly jolly mixologist, who owns The Warren Bar and Burrow in Downtown Pittsburgh, gets into the spirit of the season each year by transforming an empty storefront into a holiday-themed pop-up bar. Customers can bask in the glow of a Griswoldian amount of decorations as they sip seasonal libations from mugs shaped like Ol’ St. Nick’s noggin.

Now in its third year, Miracle on Liberty will be open from 4 p.m. to 2 a.m. every day between Nov. 23 and Dec. 31. Located in a 900-square-foot former candy shop at 717 Liberty Ave., the bar is one of more than 50 Miracle watering holes that will spring up around the globe this yuletide.

“We try to keep it fairly small and intimate,” Warren says, “because part of Miracle is getting everyone to meet each other and have fun and be cheerful.”

He has been doing pop-ups in the ‘burgh and beyond for years, and decided to launch his own holiday hangout after seeing the success his colleagues had with it in other cities.

Penn Cove Eatery, which is attached to The Warren, will serve festive sushi in the space, and there will be 12 wintry cocktails on the menu, including the Snowball Old Fashioned made with butterscotch rye, spiced Demerara, wormwood bitters and orange zest.

The Bad Santa, a beverage served piping hot, is a combination of apple cider, applejack, Manzanilla Sherry, lemon, cinnamon syrup, popcorn and bacon butter and baked apple bitters. Beer and wine also will be available.

And this year, patrons can purchase the popular Santa head mugs and other glassware — which, in previous holiday seasons, have been stolen by a bunch of drunken Grinches.

If you do stop down for a drink, you’ll be helping Warren do good: Last year’s Market Square site not only served cups of cheer, it raised $15,000 for 412 Food Rescue, a local organization that redirects potentially wasted food to people in need.

In 2018, Warren hopes to double that figure, with half going to 412 Food Rescue and the other half going to the Tree of Life Foundation in honor of the 11 people who died in the Oct. 27 mass shooting at Squirrel Hill’s Tree of Life synagogue.

A corner of Miracle that is filled with Hanukkah decorations will display pictures of the victims. And on Dec. 2, the first day of the Jewish holiday, 100 percent of the bar’s sales will be earmarked for Tree of Life Foundation.

Volunteers are welcome to stop in from now until opening day to help the Miracle staff deck the halls. Donations of holiday decorations can be dropped off at The Warren at 245 7th St.

Despite amassing thousands of strands of tinsel, twinkle lights, ornaments and animatronic Kris Kringles, Warren says he still wants more.

Taking a look around his red and green kingdom he says, “It’s like Christmas threw up everywhere!”