For the base: Add the milk to a medium saucepan, and warm it over medium-low heat until just steaming. Whisk in the cocoa, sugar, cinnamon, vanilla and malt powder. Pour into mugs.
For the adult additions: Whip the cream, sugar, chile powder and cayenne to stiff peaks, using a stand mixer. Add the tequila and salt, and whip to blend. Top mugs of hot chocolate with the chile whipped cream!
For the kids' addition: Top each mug of hot chocolate with a handful of mini marshmallows and enjoy!