For serious chocolate lovers
Boca Negra is one of the richest cakes we know (the name translates as “black mouth”). Its chocolate flavor is intense and deep.
This dense, dark cake is perfect for special occasions. Like Valentine’s Day—a holiday that cries out for chocolate.
And once you make Boca Negra Cake, you’ll be looking for new events to celebrate. So you can make it again.
Recipe: Boca Negra Cake
Our recipe is adapted from one in Baking with Julia. This cookbook, which was written by Dorie Greenspan, records all the recipes featured in the Julia Child PBS cooking show of the same name. Each episode would feature a different baker, and together they’d make one of that baker’s specialties. The baker who contributed this recipe was Lora Brody. Mrs. Kitchen Riffs is the baker in our household, and this is her adaptation.
Prep time for the cake is about 20 minutes, with baking time of around 30 minutes. Then you’ll need to let the cake cool for at least an hour after it comes out of the oven (Boca Negra Cake is best served before it’s been refrigerated; see Notes.) So the total time until you’re ready to serve will be about 2 hours (much of it unattended).
This cake serves ten to twelve (truly). Although it’s not large, it’s very rich. Leftovers keep for a few days if refrigerated in an airtight container.
- 12 ounces bittersweet chocolate
- 1 1/3 cups granulated white sugar, divided
- ½ cup dark rum
- 2 sticks unsalted butter
- 5 large eggs (consider using pasteurized; see Notes)
- 1½ to 2 tablespoons all-purpose flour
- ice cream or whipped cream for garnish (optional)
- fresh or macerated fruit for garnish (strawberries are particularly nice; optional)
- Position a rack in the lower third of the oven (remove the second oven rack or place it beneath the one you’ll be using to bake the cake; see Notes). Preheat the oven to 350 degrees F. Butter a 9-inch round cake pan and line it with waxed or parchment paper, then butter the paper. Place the cake pan in a larger, shallow pan (such as a large roasting pan with sides about 2 or 3 inches high), and set aside.
- Chop or break the chocolate into pieces of about 1-inch square (see Notes). Place the chocolate pieces in a medium- to large-sized mixing bowl.
- In a saucepan, mix 1 cup of the sugar with the rum. Heat on medium, stirring several times, until the mixture is boiling and the sugar has melted.
- Pour the sugar-and-rum mixture over the chocolate pieces and stir with a spatula or wooden spoon until the chocolate is melted.
- Cut the butter into 8 or 10 pieces, then place them in a microwave-safe container. Microwave the butter for about 15 seconds, or until it is soft but not melted. Stir the softened butter into the chocolate mixture a piece or two at a time, allowing each round of butter to melt before you add more.
- Break the eggs into the bowl of a stand mixer (or a medium-sized bowl, if using a hand mixer), and add the remaining 1/3 cup of sugar. Using the whisk attachment, beat the eggs and sugar for 2 to 3 minutes on medium (or until the eggs begin to thicken).
- Pour the egg mixture over the chocolate mixture and whisk together. Then whisk in the flour and mix until well combined.
- Pour the mixture into the prepared cake pan and smooth the top. Place the roasting pan (with the cake pan) in the oven. Pour boiling water into the roasting pan until it comes up about 1 inch around the outside of the cake pan (the cake pan may float in the water, especially if it’s a lightweight material such as silicone; this is OK).
- Bake the cake for 30 minutes—at which point it will have developed a thin crust on top. Remove the roasting pan from the oven and carefully take out the cake pan (be careful—it’s easy to burn your fingers). Place the cake pan on a wire rack to cool. Discard the water from the roasting pan.
- Place a serving plate over the cake pan and invert quickly. Remove the waxed or parchment paper from the cake. Allow the cake to cool for at least an hour (preferably until it reaches room temperature).
- Serve the cake by itself or garnish with ice cream, whipped cream, and/or fruit (such as fresh or macerated strawberries).
- For this recipe, we usually buy thin bars of Ghirardelli bittersweet chocolate and break them up by hand. But any good brand of chocolate will work. If the chocolate you buy is too dense to break by hand, just chop it with a knife.
- The original recipe for this cake calls for using bourbon. We think dark rum works better—especially since it combines so beautifully with chocolate. But use bourbon if that’s what you prefer.
- You could substitute light or amber rum in this recipe. But dark rum adds a particularly rich note. We generally use Myers’s Jamaican for baking, but any decent brand of dark rum should be fine.
- Eggs carry a slight (but real) risk of salmonella. So we suggest using pasteurized eggs when making any type of batter that you might taste raw. Although it’s unlikely the eggs you buy will be infected, why take the risk? Especially since most of us can’t make cake batter without tasting it.
- You can identify pasteurized eggs because they usually have a red “P” stamped on them.
- Make sure the water you add to the roasting pan is boiling hot. Otherwise, the cake will take much longer to bake because the water will have to heat in the oven before it starts cooking the cake.
- BTW, this cooking technique is called a “water bath” or bain-marie. Why use it? Because it allows the cake to bake in slow, gentle heat (the water never gets hotter than boiling temperature, or 212 degrees F). The cake cooks evenly in a nice humid environment, which helps prevent it from cracking and drying out.
- Why remove the second oven rack or place it beneath the one you’ll be using to bake the cake? To keep it out of your way when removing the cake from the oven. A bain-marie pan (which usually means a largish roasting pan) is unwieldy—and heavy when filled with water. So you don’t want a rack above it to get in your way when you’re trying to remove the bain-marie from the oven. Especially since those metal racks get very hot after a few minutes of baking. Mrs K R has burned her hands enough times to understand this all too well.
- Don’t over-bake this cake—it really should be done after 30 minutes. If you’re concerned, check its interior temperature with an instant-read thermometer. It should show a temperature of about 170 to 180 degrees F—which is perfect for this cake, IMO.
- The cake will be soft when you take it out of the oven, but it will set up as it cools.
- Boca Negra Cake is best when served at room temperature. But chilled works too. In fact, after the cake has been in the fridge for a few hours, it takes on the consistency of fudge. Hard to beat that!
- This cake is very rich by itself, so feel free to serve it “neat.” A garnish does add color and accent flavor, though.
- The original recipe calls for topping the cake with white-chocolate cream. That’s way too sweet for us. But we do sometimes serve it with whipped cream or vanilla ice cream if we’re feeling particularly festive.
Wow your Sweetie
“This cake is the perfect dessert for Valentine’s Day,” I said. “Deep, dark chocolate flavor that knocks your socks off!”
“It’s definitely rich and luscious,” said Mrs. Kitchen Riffs. “And a little goes a long way, doesn’t it?”
“Yes,” I agreed. “Good thing I had a small dinner. So I can squeeze in another piece of this.”
“Second slice, coming right up,” said Mrs K R. “And I’ll get you another pair of socks.”
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