Tunnel of Fudge Cake - Scratch

The famous Tunnel of Fudge cake that won the 1966 Pillsbury Bake-Off, rebuilt here entirely from scratch. The magic is in the deliberate underbaking: the edges set into a dense, chocolate cake while the center stays molten and fudgy, creating that signature gooey tunnel when you slice it.

The batter is rich, almost absurdly so. Nearly two cups of butter beaten with granulated sugar, six eggs added one at a time, powdered sugar folded in, then flour, cocoa, and a full two cups of chopped walnuts stirred by hand. The walnuts are not optional. They’re structural, helping the outer ring set while the center stays soft.

Bake for exactly 58 to 62 minutes. This is one recipe where you do not use a toothpick test. The center is supposed to be wet. A toothpick will come out gooey and that’s exactly right. Cool upright in the pan for a full hour before inverting so the fudge tunnel sets enough to hold its shape.

Pro Tips

• Do not overbake. Even 5 extra minutes can turn the fudge tunnel into just another chocolate cake.
• The walnuts must stay in the recipe. Without them, the cake structure changes and the tunnel won’t form properly.
• Cool in the pan for a full hour, no cheating. Inverting too early collapses the soft center.
• The chocolate glaze is a simple mix of powdered sugar, cocoa, and milk. Pour it over the top and let gravity do the work.

Variations

• Use pecans instead of walnuts for a slightly sweeter, butterier nut.
• Add a teaspoon of espresso powder to the batter for deeper chocolate flavor.
• Skip the glaze and dust with powdered sugar for a more rustic look.