The Old Fashioned in one of the most essential cocktails for any home bartender to know. It is a timeless cocktail that has been found on bar menus for well over a century, proving that simple cocktails are often the best cocktails. The classic dynamic of spirit, sugar, water, and bitters never fails. But modern craft cocktail culture give us imaginative riffs that elevate the familiar into something extraordinary.
The Toasted Marshmallow Old Fashioned preserves the backbone of a traditional whiskey cocktail while infusing a campfire warmth that transforms every sip into an autumn bonfire. Sweet, smoky, caramel notes pair with the vanilla depth of aged bourbon, creating a drink that feels both nostalgic and luxurious.
Looking for more Old Fashioned recipes? Try a Pumpkin Coffee Old Fashioned or a Cherry Old Fashioned
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What is an Old Fashioned?
To understand this variation, it helps to examine how to make a classic Old Fashioned. Strip away the extra fruit slices, neon cherries, and excessive soda water that contaminated the drink during the mid-twentieth century, and you are left with the purest template in bartending history. An Old Fashioned is simply a spirit seasoned with sugar and bitter botanicals, chilled and diluted with ice. Because there are no heavy fruit juices, syrups, or cream to mask the spirit, every single ingredient must carry its own weight. The sugar serves to soften the alcohol burn, while the bitters add complexity, structure, and aroma.
How to make a toasted marshmallow syrup
The defining ingredient of this specific variation is the toasted marshmallow syrup. Far superior to artificial store-bought flavorings, homemade toasted marshmallow syrup introduces a new depth of flavor. Creating it requires a quick culinary transformation. As marshmallows are exposed to open flame, the sugar content caramelizes which produces deep brown notes of rich molasses, gentle smoke, and toasted vanilla. When melted into a standard simple syrup base of equal parts warm water and sugar, these charred sugars infuse the syrup with a rich, velvety body. The resulting syrup carries the distinct campfire warmth of roasted marshmallows without making the drink taste overly sweet.
If you’re looking for a way to store your syrups, I use this syrup bottle kit which makes things easy with the included funnels and spouts.
What are bitters?
Bitters play a crucial role in balancing that sweetness. Known as the salt and pepper of the bar world, bitters are high-proof alcohol infusions packed with aromatic herbs, roots, barks, spices, and fruit peels. In a cocktail, their primary job is to bridge the gap between strong spirits and sweeteners. While traditional Angostura bitters rely heavily on gentian root and baking spices, this recipe calls for chocolate bitters. The dark, cocoa-rich bitterness acts as a counterweight to the sweet marshmallow syrup, reminiscent of the classic campfire s’more.
How to make a large clear ice cube
No elevated Old Fashioned is complete without proper ice. Making large, clear ice cubes at home may seem like an aesthetic luxury, but it serves a fundamental functional purpose. Standard freezer ice is filled with trapped air bubbles and impurities, causing it to melt rapidly and dilute your drink into a watery mess. A large, crystal-clear cube melts at a much slower rate, keeping the cocktail icy cold while preserving its strength from the first sip to the last. Achieving crystal clarity relies on directional freezing, a technique where water freezes from the top down, pushing air and impurities to the very bottom. By filling an insulated tumbler or small cooler with warm distilled water, leaving the top open, and freezing it overnight, you create a solid block of clear ice that can be carved into perfectly sized cocktail cubes.
The easiest way to make clear cubes at home are with molds that use directional freezing like this one from amazon.
Should you use Bourbon or whiskey?
When building the drink, selecting the right base spirit determines the character of the entire cocktail. While all bourbon is whiskey, not all whiskey is bourbon. Whiskey is a broad family of distilled spirits made from fermented grain mash, encompassing everything from sharp rye and smooth Irish whiskey to peated Scotch.
Bourbon, however, is an American original defined by strict legal standards. It must be made in the United States, crafted from a grain mixture that is at least fifty-one percent corn, distilled to no more than one hundred sixty proof, and aged in brand-new charred oak containers. The high corn content combined with fresh charred oak imparts natural notes of sweet vanilla, dark caramel, oaky spice, and toasted nuts. These flavor characteristics make bourbon the perfect partner for toasted marshmallow syrup and chocolate bitters, whereas a spicier rye or a smoky Scotch might clash with the sweet profile.
Pro Tips
Achieving cocktail bar quality at home comes down to a few expert practices.
Always measure your liquid ingredients precisely using a dual-sided jigger to maintain the delicate balance between spirit, syrup, and bitters.
Always stir your cocktail rather than shaking it. Shaking introduces micro-aeration and rapidly melts ice, clouding the drink and ruining its silky, heavy texture. Stirring with clean ice gently chills and dilutes the liquid while preserving its crystal clarity.
Take time with the garnish. Toasting fresh marshmallows on a bamboo skewer right before serving releases aromatic oils that set the mood before the glass even touches your lips.
Toasted Marshmallow Old Fashioned
Ingredients
- 2 oz bourbon
- ¾ oz toasted marshmallow syrup
- 2 dashes of chocolate bitters
- Garnish: toasted marshmallows
- 1 cup fresh marshmallows mini or full-sized, white
- 1 cup granulated white sugar
- 1 cup water
- 1 teaspoon pure vanilla extract
Method
- In a heavy mixing glass, combine the toasted marshmallow syrup, chocolate bitters, and bourbon.
- Fill the mixing glass three-quarters full with solid ice cubes.
- Using a long bar spoon, stir the cocktail smoothly for thirty seconds until chilled.
- Place one large clear ice cube into a double old fashioned glass and strain the liquid directly over it.
- Garnish with toasted marshmallows resting across the rim on a bamboo skewer and serve immediately.
- Toast the Marshmallows: Using your preferred method above, toast 1 cup of marshmallows until deeply golden brown and caramelized.
- Combine Sugar and Water: In a small saucepan over medium heat, combine 1 cup of sugar and 1 cup of water. Stir occasionally until the sugar is completely dissolved and the liquid comes to a gentle simmer.
- Melt in the Marshmallows: Add the warm, toasted marshmallows directly into the simmering syrup. Lower the heat to medium-low and whisk continuously for 3 to 5 minutes until the marshmallows fully dissolve into the liquid.
- Add Vanilla & Strain: Remove the pan from the heat and stir in 1 teaspoon of pure vanilla extract. Strain the syrup through a fine-mesh sieve into a bowl or jar to remove any undissolved gelatin foam or heavy char bits.
- Cool & Bottle: Allow the syrup to cool completely at room temperature before pouring it into a clean glass bottle or airtight jar.
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