Erin Mann is baking a new cake every week for a year from the "All Cakes Considered" cookbook and shares her adventures here on AnnArbor.com. Read past columns here.

Dry, outer edges surrounding a core of fudgy chocolate goodness make Tunnel of Fudge Cake a wonder of baking chemistry. Not only did it win creator Ella Rita Helfrich from Houston, Texas second prize of $5,000 in the 1966 Pillsbury Bake-Off but spurred the Bundt cake frenzy that sent every home baker to the store for their very own Nordic Ware.

1. "There's a hole in this cake."

What is it? It's a Bundt. A Bundt? -dialogue from My Big Fat Greek Wedding

To fulfill the request of the Minneapolis Hadassah Society, Nordic Ware founder H. David Dalquist created the aluminum Bundt pan in 1950. The society's members wanted an appropriate pan for baking bundkuchen, a popular German/Austrian coffeecake. Dalquist added a "t" to the German word bund and trademarked his invention and the Bundt cake was born!

Why is use of this pan so important to the final result of the cake? The shape is integral because the areas where the batter touches the pan are going to be the hottest and therefore the most well-done producing crisp, crust-like edges that support the soft fudge-y center.

2. Enough sugar to induce a diabetic coma.

Sugar is a hygroscopic substance, meaning that it attracts water molecules from its surrounding environment. The recipe contains a whopping 3-3/4 cups of sugar! Under normal baking times and temperatures, the excess sugar aids in creating a moist center and binds to the flour proteins preventing them forming gluten, the structural lattice that "sets" the cake.

3. You gotta go nuts.

The necessity of the walnuts is debatable. "All Cakes Considered" author Melissa Gray says they're optional. Shirley O. Corriher recommends adding them for enhanced flavor but offers no explanation of their chemical benefits. "The roasted nuts are really important. Without them, the cake seems ordinary, but with them, it's fantastic."

Chowhound readers discuss possible reasons the nuts are an important addition to the formation of the cake. Some hypothesized the nuts sink to the bottom of the pan and because they absorb heat, help form the dry outer edges.

One of my followers on Twitter is in support of adding nuts. Having made the cake three different times before she considered it a success, she believes omission of the nuts make it impossible to achieve a runny fudge middle.

I must confess this iconic confection had me shaking in my favorite pair of boots. I pictured a possible disastrous outcome akin to a scene from The Shining with molten chocolate-y lava pouring out of the cake and cascading over my kitchen appliances. Then I thought, it's just cake. If it goes horribly wrong I can try again. I picked myself up by my bootstraps, or apron straps rather, and got to baking.

Per Shirley's suggestion, I mixed the walnuts in a bowl with a little softened unsalted butter and sea salt and roasted them on a baking sheet for 10 minutes at 350 degrees mixing them up about half way through. Allow the nuts to cool for a bit before chopping and measuring them.

I mixed the batter according to the recipe's instructions and poured it into my pan. I checked my oven thermometer to be sure the oven temperature was 350 degrees. Oven temperature and baking time is critical to achieving the a successful tunnel of fudge.

After the minimum suggested baking time of 45 minutes, I removed the cake from the oven and set it on a rack to cool. The recipe suggests cooling the cake in the pan for at least an hour-and-a-half. I don't recommend this cake for impatient folks and/or those who don't like surprises as the wait is long and you don't really know what you're going to get until you remove the cake from the pan and cut into it.

With my roommate to witness, I cut into the cake. We were really hoping for a spectacle, but nothing oozed. Nothing gooed. Where'd I go wrong?

The inside was indeed the consistency of a block of fudge from a Mackinaw Island vacation encased by a drier outside. After all, it's not called Tunnel of Chocolate Syrup, it is called Tunnel of Fudge, and in my opinion, there was fudge. The taste and texture reminded me a lot of some of my favorite brownies, crusty on the outside and fudgy in the middle.

I found a number of recipes on the web for Tunnel of Fudge Cake. Some of the photos that accompany these recipes show a more solid fudge-like middle and others look like chocolate sundae topping oozing out of the center of the cake. Some of the recipes have slight variations. The recipe closest to the original 1966 version appears on both the Pillsbury and Nordic Ware websites and are identical to the recipe in "All Cakes Considered." I've also considered trying the recipe from CooksCountry.com and Shirley O. Corriher's "Improved Tunnel of Fudge" recipe and comparing the results.

Have you attempted the iconic Tunnel of Fudge Cake?  What were your results?

Erin Mann is a contributor for AnnArbor.com. She is a lover of all things cake and welcomes your baking wisdom. Email her at SheGotTheBeat@gmail.com or follow her on Twitter. Facebook users can also keep up-to-date with A CAKE A WEEK by joining the group.