Neil Patrick Harris and David Burtka’s Cocktail and Mocktail Recipes

Neil Patrick Harris and David Burtka know a thing or two about alcoholic and nonalcoholic pairings.

Inspired by their real-life entertaining style, the couple raise the bar on their favorite drinks in their upcoming book Both Sides of the Glass, which will be out on Tuesday, Sept. 30.

Harris, who tells PEOPLE that a drink duo “should be siblings, not twins,” handled the boozy beverages, while Burtka, who suggests “using similar base ingredients,” took care of the spirit-free sips.

One of the 70 recipes in the book is the How I Met Your Mother star’s classic Chocolate Martini that he describes as “like drinking melted chocolate with a cool sleek bite to it.” For a twist on the “indulgent” cocktail, he suggests adding homemade cinnamon syrup to it.

“Cinnamon and chocolate are a classic combo!” the star says. “But it’s definitely an option for those with a sweet tooth.”

Burtka, who is eight years sober, matches Harris’s martini with a Frozen Hot Chocolate (which he calls Cold Hot Chocolate in Both Sides of the Glass) inspired by a menu item at Serendipity 3, the longtime New York City hot spots.

“If it’s iconic enough to get a movie (see the 2001 Kate Beckinsale John Cusack rom-com Serendipity), it’s iconic enough to inspire a drink in this book,” Burtka declares.

These recipes, adapted from their collection, “take inspiration from the same place and then do their own thing,” says Harris.

David Burtka’s Frozen Hot Chocolate

2 cups crushed ice

3/4 cup milk (preferably whole milk)

1/2 cup hot chocolate mix

Whipped cream

Ground cinnamon or cocoa powder (optional)

1. Place ice, milk, and hot chocolate mix in a blender; blend until consistency resembles a slushy, 8 to 10 seconds. Pour into your glass of choice, and top with whipped cream and a dusting of cinnamon or cocoa powder (if using). Serve immediately. 

Makes: 1

Active time: 5 minutes

Total time: 5 minutes

Neil Patrick Harris’s Chocolate-Cinnamon Martini

1 cup water

1/2 cup granulated sugar

1/2 cup packed light brown sugar

3 to 4 (4-in.) cinnamon sticks

1/4 cup (2 oz.) vodka

2 Tbsp. (1 oz.) chocolate cream liqueur, like Baileys Chocolate Liqueur

Ground cinnamon

1. Heat water, granulated sugar, and brown sugar in a small saucepan over medium, whisking constantly, until sugars dissolve, 1 to 2 minutes. Add cinnamon sticks, and bring to a gentle boil over medium. Reduce heat to low; cover and simmer for 15 minutes. Remove from heat; cover and let steep for 1 to 2 hours. Strain cinnamon syrup into an airtight heatproof glass container; let cool completely in refrigerator, covered, where it will keep for about 1 month.

2. Pour vodka, liqueur, and 1 tablespoon cinnamon syrup into a cocktail shaker with ice. Cover and shake until chilled and mixed, about 15 seconds. Strain into a martini glass. Shake a dusting of ground cinnamon on top.

Makes: 1

Active time: 15 minutes

Total time: 1 hour, 30 minutes