Impossible Hot Fudge Pudding Cake

This pudding cake pulls off a genuine magic trick in the oven. You mix a simple batter in the pan, sprinkle sugar and cocoa on top, pour hot water over everything, and walk away. Don’t stir. As it bakes, the batter rises to form a firm, cakey top while the sugar, cocoa, and water sink below and transform into a thick, gooey fudge sauce underneath.

The science is straightforward. The baking mix contains leavening that pushes the batter upward while the heavier sugar-cocoa-water mixture drops to the bottom and caramelizes into pudding. Two layers from one pan, no separation required.

Spoon it into bowls while it’s still hot. The fudge sauce is liquid and pourable right out of the oven, which is exactly what you want pooling around each scoop.

Kitchen Tips

• Do not stir after pouring the hot water over the top. Stirring mixes everything together and you lose the two-layer separation that makes this recipe work.
• Use hot water, not cold or warm. Hot water dissolves the sugar and cocoa on top faster, which helps them migrate to the bottom during baking.
• The top should be firm to the touch when done, but the bottom will still be liquid. That’s correct. It’s a pudding cake, not a regular cake.
• Serve with vanilla ice cream. The cold ice cream melting into the hot fudge sauce is the whole point.

Variations

• Add a teaspoon of instant espresso to the cocoa mixture for a mocha pudding cake.
• Stir a handful of chocolate chips into the batter before adding the topping for extra pockets of melted chocolate.
• Use coffee instead of hot water for a deeper, more complex chocolate flavor.