Reserve half your marshmallows for the top layer added halfway through baking to prevent them from burning while ensuring gooey centers and crispy edges throughout the cake.

Whisk the hot cocoa mix with a small amount of warm milk before adding to the batter to eliminate lumps and distribute the cocoa flavor evenly throughout.

Mix only until ingredients are just combined after adding the milk mixture—overmixing develops gluten and creates a dense, tough cake instead of the tender crumb you want.

Serve with a generous dollop of chilled whipped cream immediately after the cake cools slightly to create a delightful temperature and texture contrast that mimics the hot cocoa experience.

The cake is perfectly baked when the edges pull away from the pan and a toothpick inserted near the center has a few moist crumbs—this prevents dryness while ensuring the center sets properly.