Flan Imposible (Impossible Chocolate Flan)
This recipe is excerpted from My Sweet Mexico by Fany Gerson. Copyright © 2010 by Fany Gerson. Excerpted by permission of Ten Speed Press, a division of Random House, Inc.
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Credit: Ed Anderson
1 cup cajeta, homemade or store-bought
FOR THE CAKE
¾ cup sugar
¾ cup all-purpose flour
1/3 cup unsweetened cocoa powder, preferably Dutch processed
½ teaspoon baking soda
¼ teaspoon baking powder
Pinch of salt
½ cup buttermilk
3 tablespoons vegetable oil
1 egg, at room temperature
½ teaspoon pure vanilla extract
FOR THE FLAN
1 (12-ounce) can evaporated milk
1 (14-ounce) can condensed milk
4 eggs
½ teaspoon pure vanilla extract
½ teaspoon salt
¾ cup coarsely chopped, toasted pecans or walnuts, for garnish
Preheat the oven to 375°F. Lightly grease the bottom and sides of an 8-inch cake pan.
Pour the cajeta over the bottom and sides of the cake pan using a brush or the back of a spoon (you can heat the cajeta very slightly in the microwave so that it is easier to spread).
Make the cake: combine the sugar, flour, cocoa powder, baking soda, baking powder, and salt in a large bowl and whisk until well blended. In a separate bowl, whisk together the buttermilk, vegetable oil, egg, and vanilla. Add to the flour mixture, whisking until thoroughly combined. Pour the cake batter into the pan and set aside.
Make the flan: combine the evaporated milk, condensed milk, eggs, vanilla, and salt in a blender and blend until there are no visible lumps. Pour gently over the cake batter.
Cover loosely with foil, place in a large baking dish, and fill the baking dish with hot water so that it comes halfway up the sides. Bake until a toothpick inserted into the center comes out clean, about 50 minutes.
Remove the cake pan from the baking dish and allow to cool for at least 4 hours or refrigerate overnight. To unmold, lightly pass a warm knife around the edge, place a plate or dish on top, and carefully but rapidly flip over. Garnish with the toasted nuts. Serve cold or at room temperature.

But if you want to make things easy on yourself, we recommend purchasing some from Fat Toad Farm. http://www.fattoadfarm.com/goats-milk-caramel/
In a pinch, store-bought dulce de leche would be a fine substitute.
Hope that helps!
Ganda
I like chocolate cake and i like flan. just not this one. the Spanish flan
posted here is excellent.
The recipe itself was okay, the cake wasn't super chocolatey which I liked since I'm not a huge chocolate fan.