Ingredients

• 3/4 cup powdered sugar
• 1/2 cup high-quality cocoa powder
• 3 ounces bittersweet chocolate, coarsely chopped
• 2 teaspoons cornstarch
• 1/8 teaspoon fine sea salt
• 1 vanilla bean, split lengthwise
• 1 cup whole milk
• Whipped cream, marshmallows, and cocoa powder (for serving)

Instructions

1. Combine powdered sugar, cocoa powder, chocolate, cornstarch, and sea salt in a food processor. Scrape in vanilla seeds; discard pod. Blend until mixture is smooth and powdery, about 1 minute.
2. Make the hot chocolate: Bring milk to a simmer in a small saucepan over medium heat. Whisk in 3 Tbsp. hot chocolate mix and cook, whisking occasionally, until mixture returns to a simmer and hot chocolate mix is dissolved and thickens slightly, 1-2 minutes. Transfer hot chocolate to a mug. Top with whipped cream and marshmallows and dust with cocoa powder.
3. Bring milk to a simmer in a small saucepan over medium heat. Whisk in 3 Tbsp. hot chocolate mix and cook, whisking occasionally, until mixture returns to a simmer and hot chocolate mix is dissolved and thickens slightly, 1-2 minutes.
4. Transfer hot chocolate to a mug. Top with whipped cream and marshmallows and dust with cocoa powder.
5. Do Ahead Hot chocolate mix can be made 2 months ahead. Store in an airtight container at room temperature, or freeze up to 3 months.
6. Hot chocolate mix can be made 2 months ahead. Store in an airtight container at room temperature, or freeze up to 3 months.