Name: Lisbon Chocolate Cake Recipe
Prep time: 25 min
Cook time: 20 min
Total time: 3 h 10 min
Cuisine: Portuguese
Ingredients: 1/2 cup (115 grams) unsalted butter (1 stick), cut into chunks, plus more for greasing the pan; 1/3 cup (30 grams) unsweetened cocoa powder; 1 1/2 tablespoons cornstarch; 1/4 teaspoon baking powder; 1/4 teaspoon fine sea salt; 5 ounces (140 grams) semisweet or bittersweet chocolate, coarsely chopped; 1/2 cup (100 grams) granulated sugar; 3 large eggs, chilled; 1 3/4 cups (420 milliliters) heavy cream, divided; 6 ounces (170 grams) semisweet or bittersweet chocolate, finely chopped; 3 tablespoons unsweetened cocoa powder

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Introduction

The Lisbon Chocolate Cake is a rich, fudgy dessert that perfectly balances intense chocolate flavor with a light, creamy mousse topping. This elegant cake is ideal for special occasions or any time you want to impress with a decadent homemade treat.

A slice of chocolate mousse cake sits on a white plate, showing two clear layers: a thick, dense dark brown chocolate base at the bottom and a lighter, airy chocolate mousse layer on top, dusted with a fine layer of cocoa powder. The slice has a smooth, creamy texture on the mousse, while the bottom looks rich and slightly crumbly. In front of the slice is a fork with a chunk of cake, also showing the two layers, resting on the plate with some scattered crumbs. The background surface is a white marbled texture with another white plate holding more cake slices blurred in the distance. photo taken with an iphone --ar 4:5 --v 7

Ingredients

1/2 cup (115 grams) unsalted butter (1 stick), cut into chunks, plus more for greasing the pan
1/3 cup (30 grams) unsweetened cocoa powder
1 1/2 tablespoons cornstarch
1/4 teaspoon baking powder
1/4 teaspoon fine sea salt
5 ounces (140 grams) semisweet or bittersweet chocolate, coarsely chopped
1/2 cup (100 grams) granulated sugar
3 large eggs, chilled
1 3/4 cups (420 milliliters) heavy cream
6 ounces (170 grams) semisweet or bittersweet chocolate, finely chopped
3 tablespoons unsweetened cocoa powder

Instructions

Step 1: Preheat the oven to 325°F (165°C) and center a rack. Butter a 9-inch cake pan, line it with parchment paper, and butter the paper as well.
Step 2: In a medium bowl, sift together the cocoa powder, cornstarch, baking powder, and salt. Whisk to combine evenly.
Step 3: Melt the 1/2 cup butter and the coarsely chopped chocolate in a heatproof bowl set over simmering water, stirring often until smooth and glossy. Remove from heat and stir in the sugar.
Step 4: Beat in the eggs one at a time, mixing energetically and beating for 1 minute after adding the last egg until the mixture resembles pudding. Fold in the dry ingredients gently.
Step 5: Pour the batter into the prepared pan and tap the pan on the counter a couple of times to settle. Bake for 18 to 20 minutes, until a tester comes out clean or with only a tiny streak of chocolate. Cool in the pan for 5 minutes, then unmold and cool to room temperature. Clean and dry the pan.
Step 6: For the ganache, pour 1 1/4 cups of heavy cream into a small saucepan and refrigerate the rest. Heat the cream over medium heat until scalding, then remove from heat and stir in the finely chopped chocolate until melted and smooth. Transfer to a bowl and chill, whisking every 10 minutes, until thickened, approximately 50 to 60 minutes total.
Step 7: Cut two 3-by-16-inch strips of parchment or foil and cross them inside the cake pan to support the cake. Place the cooled cake back into the pan.
Step 8: Whip the remaining 1/2 cup cream until medium peaks form. Gently whisk the ganache until spreadable, then fold in the whipped cream gently with a spatula. Spread this mousse over the cake evenly.
Step 9: Refrigerate the cake for at least 2 hours or cover and keep for up to 2 days. Before serving, sift the cocoa powder evenly over the top.
Step 10: Run a table knife along the sides of the pan, lift the cake out using the parchment or foil handles, discard the strips, and transfer to a serving plate. Clean a long knife under hot water before cutting and dry it between slices for clean cuts.

Tips & Variations

Use high-quality bittersweet chocolate for the best flavor and a more intense chocolate experience.
If you don’t have cornstarch, you can substitute with an equal amount of all-purpose flour, but the texture may be slightly different.
Allow the cake to come to room temperature before serving for a softer texture and richer taste.
For a decorative touch, garnish with fresh berries or a dusting of powdered sugar instead of cocoa powder.

Storage

Store the Lisbon Chocolate Cake covered in the refrigerator for up to 2 days. The mousse topping stays fresh and creamy when chilled. Before serving, remove the cake from the fridge about 20 minutes to let it warm slightly for the best flavor and texture. Leftover cake can be kept refrigerated and eaten within this time frame; avoid freezing as it may alter the mousse consistency.

How to Serve

A slice of two-layer chocolate cake sits on a white plate, placed on a white marbled surface. The bottom layer is dark and dense with a rich, fudgy texture, while the top layer is a lighter, creamy chocolate mousse, dusted evenly with cocoa powder. In front of the slice, a fork holds a small bite of the cake, showing the moist and soft interior. Crumbs and cocoa powder are scattered lightly around the plate. In the background, out of focus, there is another white plate with more cake. photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use milk chocolate instead of bittersweet?

While milk chocolate can be used, it will make the cake sweeter and less intense in chocolate flavor. Bittersweet or semisweet chocolate is preferred for balancing richness and sweetness.

How do I know when the cake is done?

The cake is ready when a tester or toothpick inserted into the center comes out clean or with just a tiny streak of chocolate. The cake should be moist but set and not wet or raw-looking.