PREPARE THE HOT COCOA
In a medium saucepan, combine evaporated milk, regular milk, and heavy cream over medium heat.
Stir in brown sugar, cocoa powder, and a pinch of salt until smooth and warmed through.
Add semi-sweet chocolate and whisk until fully melted.
Stir in vanilla extract, adjust sweetness as desired, and keep warm on low heat.
MAKE THE MARSHMALLOW FLUFF
In a mixing bowl, add egg whites and cream of tartar. Whisk until the mixture becomes bubbly and foamy.
In a saucepan, combine water, sugar, and corn syrup. Heat over medium heat, stirring until the sugar dissolves.
Allow the mixture to simmer without stirring further, until it reaches about 240°F or 115°C using a candy thermometer.
With the mixer running at medium speed, slowly stream the hot syrup into the egg whites. Avoid pouring too quickly to prevent scrambling.
Once all the syrup is added, increase the mixer speed to high and beat until the mixture is glossy and holds stiff peaks.
ASSEMBLE AND TORCH
Pour the prepared hot cocoa into cups or mugs.
Transfer the marshmallow topping to a piping bag fitted with a star or round tip.
Pipe the marshmallow around the rim of each cup.
Use a kitchen torch to toast the marshmallow until golden brown.
Serve immediately and enjoy your elevated hot cocoa experience!