Cake Ingredients

• 540g (2 1/4 cups) water, boiling hot
• 117g (1 1/2 cup) black cocoa powder*
• 256 g dark chocolate, chopped into small pieces**
• 662g (3 cups) brown sugar (light or dark)
• 2 1/4 teaspoons kosher salt (I use Diamond Kosher)
• 320g (1 1/2 cups) oil, flavorless such as canola or veg
• 63g (4 1/2 tablespoons) sour cream
• 405g (3 1/2 cups) all-purpose flour
• 4 1/2 teaspoons baking powder
• 90g (4 1/2 large) egg yolks
• 450g (9 large) eggs

Cake Instructions

1. Move your oven rack to the lower third position. Preheat the oven to 350°F (180 °C).

2. Butter the insides of a cake pan and line the bottom with a circle of parchment paper. Dust a very light coating of flour along the sides the pan.

3. In a large mixing bowl, add the boiling water, black cocoa, chopped dark chocolate, brown sugar, and salt. (Make sure the water is boiling hot so it will melt the chocolate.) Whisk until thoroughly combined. Set aside your bowl for at least 5 minutes for the chocolate flavor to deepen and bloom.

4. Add oil and sour cream to the bowl of chocolate and whisk. You may see the oil separate on the top, but keep whisking until it's slightly thicker, glossy, and thoroughly combined.

5. Whisk in the all-purpose flour and baking powder until no traces of flour remain.

6. Whisk in the yolks and egg(s) for about a minute until the batter is thoroughly mixed and velvety black. (It may start to bubble; that's normal. It's the baking powder interacting with the other ingredients. You can tap those out in your pan or wait about 5-10 minutes before pouring the batter in your pans to get super smooth cake tops, if that's what you're going for.)

7. Pour the batter into the prepared pan.

8. Bake for about 35-40 mins or until a skewer inserted in the center comes out with a few crumbs attached. (Start around 30 mins.) If you do not have three pans, you can bake them one after another. Just let the batter sit out at room temp until you're ready to bake it.

9. Move the pan to a cooling rack and allow the cake to cool in the pan completely.

10. Loosen the edges of the cake using an offset spatula or butter knife, and flip the cake out onto a cooling rack so you can peel off the parchment bottom. Make sure it is completely cool before assembling and/or frosting.

💌 Cake Notes from Adriana

*Black cocoa powder is natural cocoa that has been alkalized, which changes specific properties of the cocoa, including its solubility, flavor, and color. It's tough to find in stores, so I buy mine online. The one I use is from Cocoa Trader on Amazon, but King Arthur Baking also has great black cocoa. Also - try always to measure cocoa powder by weight if you can. The powder is so fine that it's hard to get the correct measurements using volume.

**Chocolate pieces are hard to measure using volume (cups, etc.), so I only use weights for chocolate pieces in my recipes. In my recipes, my dark chocolate is usually either Trader Joe's Dark Pound Plus bars or Ghirardelli. Other bakers have told me that chips work too, but I have yet to try that.