Hot Fudge Sundae Cake

This is one of those magic chocolate cake recipes where you pour hot water over raw batter and somehow the oven sorts it all out. Forty minutes later, you’ve got a layer of soft chocolate cake sitting on top of a pool of thick, hot fudge sauce. No separate sauce recipe needed.

The science behind it is straightforward. The brown sugar and cocoa sprinkled on top dissolve into the hot water during baking. As the cake batter rises, it pushes up through the liquid, and the sugar-cocoa-water mixture sinks to the bottom and thickens into a glossy pudding sauce. It looks like a mess going into the oven and comes out looking like sorcery.

Let it rest 15 minutes before serving. That cooling time lets the sauce thicken from pourable to spoonable, and the cake firms up enough to hold its shape when scooped.

Kitchen Tips

• Use an ungreased pan. The batter needs to cling to the sides as it rises, and grease will make it slide back down.
• Don’t stir after pouring the hot water. It’s supposed to sit on top of the batter in a layer. The oven does the mixing.
• Invert each square onto the plate so the fudge sauce is on top, then add ice cream. The sauce underneath is the whole point.
• This is best served warm. The sauce solidifies as it cools completely, losing that gooey, sundae quality.

Variations

• Use peanut butter chips instead of nuts for a chocolate-peanut butter version.
• Add a teaspoon of espresso powder to the dry ingredients for a mocha twist.
• Serve with whipped cream instead of ice cream if you want a lighter topping.