How To Make a Molten Chocolate Bundt Cake

When Ella Helfrich of Houston, Texas, won second prize in the Pillsbury Bake-Off® Contest in 1966 with her Tunnel of Fudge cake, she made more than just a winning cake — she created both a 1960s phenomenon and a memory that lingers so strongly for a generation of cake bakers and eaters that even though the ingredients she used are long off the market, many bakers to this day tackle her curious recipe. I recently joined those bakers. This is the story of how you can make a delicious, fudge-filled chocolate Bundt cake that’s all about the chocolate and fudge filling without a nut in sight, and that tastes like that memory.

Pillsbury made a basic frosting mix for years, and the clever Mrs. Helfrich combined a packet with Pillsbury’s chocolate cake mix and baked it up in a newfangled, all-but-unknown decorative pan with a hole in the middle. The cake was dense with a variety of sugars, and a tunnel of fudgy gooey chocolatey goodness was the secret inside this innovative cake. Everyone wanted to make the cake. Bundt pan sales skyrocketed and the recipe itself was a national sensation.

No one could pinpoint how the magic tunnel o’ yum was created, but everyone reveled in the results.

Then came a crushing blow to the tunnel o’ fudge bakers: Pillsbury dropped the more labor-intensive dry frosting packet and marketed the easier-to-use canned frosting. Home bakers suffered trying to recreate the cake, and they caused such an uproar that the company brought the frosting mix back for awhile and developed its own “from-scratch” version of the cake, which did not require their soon-to-be obsolete mix.

Not every baker was happy. There arose a zillion recipes for the cake, but most have glaring issues like gloppiness, soggy bottoms, runny middles, burnt outsides, or all of the above. Many use a variety of additive-laden packaged items and pudding, not fudge — none of which the original used — and they didn’t really create the same taste and texture. The biggest issue was that most offered inconsistent results. Then came a food scientist named Shirley O. Corriher.

In 2007 Corriher wrote Bakewise: The Hows and Whys of Successful Baking and offered up her brilliant and innovative version of the Tunnel of Fudge Cake. She upended the recipe by throwing all logic about cake baking ratios out the window, upping the sugar, enriching it with egg yolks, and baking it just so the fudgy center appeared like magic. It’s a great recipe, if quite sweet. A key to both her cake and the Pillsbury version is the use of nuts. Lots and lots of nuts. The nuts provide physical structure. My quest was different. This was to be a cake that didn’t need the architectural engineering of nuts.

My recipe tester is a veteran baking chef-instructor. When I showed her my first three ideas for this cake, she checked the baking numbers and was aghast, but game. Not one fit any ratio of any cake she had ever made. We talked for hours and consulted textbook after textbook. There was no doubt that the cake would need odd ratios, but the issue was twofold: Could I come up with a hack to create a great cake and great filling, and could I make it all without the nut scaffolding? I revised and recalculated.

None worked as planned. My dense ganache filling was absorbed by the cake, my fudge candy dissolved, and the fudge-brownie based versions wouldn’t cook enough to invert and remove from the pan without oozing like mad. They were all delicious, mind you, but the texture was never right. That’s not good enough to make a memory live again.

Oh, Mrs. Helfrich, some 11 cakes later, I was checking numbers, and lo and behold I realized that I should probably try to use the best version I had come up with and see if it worked with nuts the classic way, and deal with one problem at a time. I added 2 1/2 cups of toasted chopped pecans and, darn, that recipe worked great, as if it was the original.

Note to baker: For a nut-filled version, go ahead and add that 2 1/2 cups of toasted chopped pecans.

I thought about what to do to make the darn thing without the nut scaffolding. I tried baking cakes with some logistical changes, like heating the pan, popover-style, before adding the batter, but the results were too inconsistent. I was many, many weeks in and now baking two cakes a day, and no one in my house or at my catering job wanted to eat it anymore. I woke up at 4 a.m. to bake two cakes before we attended an afternoon wedding. Obsessed? Just a wee bit.

Four more cakes with just a few tweaks and finally, finally, it worked. No nuts and it worked. The cake held up. I baked it twice again and had my sister, who does not bake, bake it. Sure, it sank a bit every time on the fudgy part, as does every Tunnel of Fudge cake I had ever seen. This cake had a distinct fudgy center, and a cake outside that was moist and cooked. It was easy to cut through and serve beautiful slices.

I must thank Ms. Corriher. Some technical advice is absolutely taken from her version, like baking the cake for a precise amount of time and not checking for doneness and also allowing it to cool completely in the pan, but mostly and yet again, what I learned was her scientific approach to baking. I hope you love it as much as we do in my kitchen.

1. Scoop the batter in and smooth so the areas around the edges of the cake pan are less full.
2. Bake the cake on the oven’s middle rack, and about halfway through the baking, slide a casserole dish filled about two-thirds of the way with warm water onto the rack below the cake. It will boil and add humidity to the oven and help the cake stay moist. Do not add it at the beginning. You have to let the sides, bottom, and top of the cake set well first, so adding the pan of water at the 25-minute mark works best.
3. Poke holes in the finished cake around the edges of the entire pan. The ring of ooey-gooey chocolate in the middle of the cake sinks big time. While the cake is piping hot, poking some holes near the pan’s edges helps let that hot air out faster, so it catches up a bit with the center. The cake’s top will not be flat when it’s in the pan, but that’s just fine.
4. If the cake has sunk more than you like, while it is still warm, if you have some pie weights or a pie weight chain, you can cut a parchment sheet to fit the tube pan (complete with a hole in the center), slide it on top of the cake, and place some pie weight around the inner and outer edges. Leave them there while the cake cools, 3 to 4 minutes.

This cake was delicious without the glaze, but the glaze does dress it up and adds a milkier chocolate layer of flavor. It’s really up to you if you want to gild this lily. Just make sure to have plenty of whipped cream or ice cream on hand and simply enjoy.