We all have one -- a cooking fantasy -- where you think "if only I had the time and the occasion, I would make something really spectacular."

My foray into fantasyland started when my good friend Jan asked me to bake a dessert for a dinner party she had no intention of inviting me to. This was forgivable only because out-of-town friends were visiting and invited their friends. I accepted because, while I am a mediocre cook, I am an occasional baker of spectacular desserts of a certain, chocolate type. I felt breezy and confident -- and didn't have a clue what I was in for.

I wanted something swank, showy and dense. I wanted a challenge. I got to work on a Tuesday. After browsing my 26 baking cookbooks, I pick up "Death by Chocolate," a 1992 coffee-table book by Marcel Desaulniers. I find my version of the "Moby-Dick" white whale; my Everest.

Any of the different elements that make up the cake could be the substantial part of -- or even the whole of -- a normal dessert. Mocha mousse, chocolate mousse, cocoa meringue, chocolate ganache, brownies, mocha rum sauce. How hard could it be -- baking is just about following directions, right?

Wednesday: I know I am in trouble when the recipe's instructions include the phrase "Day One." First, figuring that a chocolate dessert lives or dies by the quality and intensity of the chocolate inside, I decide to use the Valrhona French chocolate bar my husband gave me for my birthday, supplemented with Lindt chocolate, to bring average chocolate density to 66 percent -- a little below the optimum of 70 percent, but it'll do.

Thursday: I buy additional chocolate, along with 2 quarts of whipping cream, 2 dozen eggs and sour cream. Reasoning that I want the cake as fresh as possible, I ignore the instructions telling me to make the brownie layers today. I later find out that is a big mistake.

Friday, 7 p.m.: My goal is to make three of the layers -- a cocoa meringue and a brownie that will be sawed in half to make two layers. The meringue needs 21/2 hours to bake, so I make it first.

I remember why I hate pastry bags as I try to "start in the center and pipe a 3/4-inch-wide spiral of the meringue toward the outside of the 9-inch (traced parchment) circle."

The brownies seem easier -- I make brownies all the time. But this recipe is a bit more exacting. Instead of the typical brownie recipe, this one uses semisweet and unsweetened chocolate and cocoa powder, as well as sour cream and butter.

Bleary-eyed but feeling good at 12:08 a.m., I pull the brownies out of the oven and turn out the light.

Saturday, 7:45 a.m.: I'm already behind schedule. My optimism of last night is gone. In the light of day, the meringue is not in an elegant spiral. It looks more like a beige cow pie. And the brownie layer is now concave; it seems too thin to cut.

But I move on to tackle the chocolate mousse, which is supposed to be piped on top of the cake, the piece de resistance. This mousse has both egg whites and whipping cream. I follow the directions scrupulously -- but something goes horribly wrong. It isn't that even light-brown color I see in the glossy photograph -- it's speckled brown and white, sort of a chocolate chip and whipped cream meringue. Where did I go wrong? Repair is underway.

Noon: I start on the ganache. This, at least, goes well -- after all, how hard is it to combine hot cream and chocolate? With 22 ounces of chocolate, heavy cream and butter, this seems like the most decadent layer of all. I figure this part alone cost about $20.

With my heart in my mouth, I tackle the mocha mousse -- the essential middle layer. This has 14 ounces of chocolate, egg whites and heavy cream, and this time it works. I take a look back at my plain chocolate mousse and try a brief test: Can I pipe it into fancy stars like the ones in the glossy picture? The chunks of chocolate clog the tip and I start again.

Finally, I'm ready for the critical assembly process in the springform pan.

Step one is to dissect the brownie layer. There is a hint printed alongside the recipe: Place toothpicks in the side of the brownie as a guide to halve it horizontally. When I start sawing, I realize that I should have measured the toothpick distances better and the "half" where the brownie layer has sunk is less than a half-inch thick in the center. Instead of two identical flat layers, I have one lumpy layer and some thin slivers. I put the thicker one on the bottom.

Next, a layer of the ganache.

2 p.m.: Except to sleep, I have not left the kitchen in the past 19 hours -- and I still think I might not make it. I'm staring at another page of recipe directions. I read: "Trim the cocoa meringue with a serrated knife so that it will fit tightly into the pan." In a mastery of understatement, author Marcel (we're on a first-name basis now) says "baked meringues are very brittle." As I trim, my dreams and my meringue crumble. I place the pieces of meringue over the ganache layer and hope that they, too, will magically reassemble into the lovely solid and crunchy heart of the cake.

2:37 p.m.: I call Jan and tell her she might consider serving the dessert in bowls.

Next is the mocha mousse layer, which, in my version, will be the cement for the meringue shards. That's followed by what I'm now thinking of as my barely there brownie, then another layer of ganache (which actually hides the crumbs pretty well).

3 p.m.: It's in the refrigerator to chill for an hour. I tackle the mocha rum sauce that's supposed to puddle in the middle of a 10-inch plate, with a cake slice gently placed on top.

4:15 p.m.: I pipe the chocolate mousse "flowers" on the top and drive to Jan's with my creation. I pipe the mousse stars. So, it's a little less glamorous than the picture, but the final layer of ganache has hidden all my sins and the finished product actually looks like a fancy chocolate cake.

11 p.m.: The guests are still there, but Jan calls to tell me the cake was a hit. I ask if there's any left. Oh, yes, I'm told, they ate only half. At 862 calories for even a thin slice, it was too rich. She suggested that next time, I add a little whipped cream on top.

Next time?

Peggy Girshman is the assistant managing editor of NPR News and a chastened cake baker.

Hidden beneath that chocolate ganache are seven layers -- every one of them made of chocolate.