Cakes were the go-to potluck dessert when I was young, so it was no surprise to see a bunch of cake recipes in Grandma's box. Some of them were duplicates, or so close to one another that I didn't feel the need to test both. Others, I tasted with my eyes and decided to take a pass. (Fruitcake, anyone? I didn't think so. Also, why is mincemeat so expensive?)
Anyhow, this recipe ended up being the last untested cake in Grandma's box, last because, frankly, it didn't sound good. I read the recipe and found that it was a fairly basic chocolate cake with the addition of one out-of-the-ordinary ingredient--mashed potatoes--but I still wasn't thrilled about trying it.
The name would have to go. I needed something more enticing--and more descriptive because there was much more to this cake than just potatoes. I crowd-sourced name suggestions, and my sister came up with this one: Grandma's Secret Chocolate Cake.
Now, that was more like it. Who doesn't love chocolate and also secrets?
The first thing I needed was mashed potatoes. I didn't have any leftovers, so I cut up two medium potatoes and cooked them until they were tender. I then mashed them with a little butter and milk.
While they cooled, I moved onto the next step, which was to beat together the shortening and sugar.
I added the potatoes and beat them in. The mixture looked like, well, mashed potatoes.
Next, I added the eggs and vanilla and beat that well.
The next step was to mix the flour, baking soda, salt, and cocoa powder. The recipe said to measure the cocoa powder by heaping tablespoons. That system didn't seem very precise, so I measured it out again and found that 1/3 cup works just as well.
I stirred the dry ingredients together.
The recipe didn't say to add the flour mixture alternately with the liquid, but that seemed like a good idea. The liquid the recipe called for was the typical substitute for buttermilk: plain milk mixed with vinegar.
I had buttermilk on hand, so I thought, Why not use that? The real thing is always better than the substitute. I sprinkled about half of the flour mixture into the batter, beat that in, added the buttermilk, then beat in the rest of the flour mixture. The batter was complete.
There was no pan size listed, which was typical of one of Grandma's recipes, but I was sure this cake would have been baked in the standard 9 x 13-inch pan we always took to potluck gatherings.
However, I decided to get fancy and bake the cake in 9-inch rounds that would then be layered on top of each other. I prepared the pans by spraying them with nonstick spray and lining them with a circle of parchment.
I set the timer for the lowest time listed on the card, but the cakes were nowhere near done when it went off. It took the full 35 minutes to completely bake the cakes. Because I don't often make layer cakes, I flubbed the turning-out process. Fortunately, they didn't break too badly.
I also tried a different kind of frosting from my usual, and it looked a little waxy on the finished cake.
But the taste was the thing that mattered, right? That was the mantra I kept repeating as I cut some slices, served them to the family, and waited to hear their thoughts.
Everyone liked it. They said it was light and fluffy, and I agreed. It was moist, too, but not quite as moist as I would have liked. I found myself reaching for a glass of water to wash it down.
There was a solution to that problem, one I'd tried on Marble Cake that had turned it into Superior Marble Cake. So, the next day, Grandma's Secret Chocolate Cake went back to the drawing board.
As with Superior Marble Cake, I replaced the shortening with butter, which I reduced, and then added a little oil. This time, I spread the batter into a square pan because I'd made half the recipe for the test. I also went back to my usual chocolate frosting recipe, which can be found here.
Now, that was a moist and tender chocolate cake.
The family members who tested this version all agreed that it was even better than the one they'd tasted the evening before. Mashed potatoes do make for a moist and fluffy cake, but replacing the solid fat with a little oil elevates this recipe into the truly delicious.
Try it. You'll be glad that the secret is now out.