Quick Recipe Version (TL;DR)

Yield: 8 servings
Prep Time: 20 minutes
Cook Time: 25 minutes
Total Time: 2 hours 45 minutes (includes cooling)

Quick Ingredients

8 oz (225 g) bittersweet chocolate, 60–72% cacao, chopped
1/2 cup (115 g) unsalted butter, plus more for greasing pan
3/4 cup (150 g) granulated sugar
4 large eggs, at room temperature
3 tbsp (15 g) unsweetened cocoa powder, plus extra for dusting pan
1 tsp pure vanilla extract
1 tsp instant espresso powder (optional)
1/4 tsp fine sea salt
Powdered sugar, for dusting
Optional: softly whipped cream and fresh berries, for serving

Do This

1. Preheat oven to 325°F (163°C). Grease an 8-inch (20 cm) round pan, line bottom with parchment, and dust with cocoa.
2. Gently melt chocolate and butter together until smooth. Stir in vanilla, espresso powder, and salt; let cool slightly.
3. Beat eggs and sugar on high speed 5–7 minutes until very thick, pale, and tripled in volume.
4. With mixer on low, slowly pour in the warm chocolate mixture. Sift in cocoa powder and gently fold just until combined.
5. Pour batter into pan and smooth top. Bake 22–27 minutes until puffed with a delicate crackly top and a slight jiggle in the center.
6. Cool 15 minutes in pan, then carefully unmold. Cool completely at room temperature (at least 1½ hours), then dust with powdered sugar.
7. Slice with a warm knife and serve at room temperature or slightly chilled with whipped cream and berries.

Why You’ll Love This Recipe

Flourless and naturally gluten-free, with a dense, mousse-like center and an ultra-thin crackly top.
Intensely bittersweet chocolate flavor boosted with cocoa and optional espresso powder.
Deceptively simple: one pan, no special equipment beyond a mixer, and bakes in under 30 minutes.
Elegant enough for dinner parties yet easy enough for a weeknight treat.

Grocery List

Produce: Optional: fresh berries (raspberries, strawberries, or mixed berries) for serving.
Dairy: Unsalted butter; heavy cream (if making whipped cream).
Pantry: Bittersweet chocolate (60–72% cacao), granulated sugar, powdered sugar, unsweetened cocoa powder, instant espresso powder (optional), pure vanilla extract, fine sea salt.

Full Ingredients

For the Flourless Chocolate Cake

8 oz (225 g) bittersweet chocolate, 60–72% cacao, finely chopped
1/2 cup (115 g) unsalted butter, cut into pieces
3/4 cup (150 g) granulated sugar
4 large eggs, at room temperature
3 tbsp (15 g) unsweetened cocoa powder
1 tsp pure vanilla extract
1 tsp instant espresso powder (optional, enhances chocolate flavor)
1/4 tsp fine sea salt

For the Pan and Finishing

1–2 tsp unsalted butter, for greasing pan
1–2 tsp unsweetened cocoa powder, for dusting pan
Powdered sugar, for dusting the top
Optional: softly whipped cream, lightly sweetened
Optional: fresh berries for serving

Step-by-Step Instructions

Step 1: Prepare the pan and preheat the oven

Preheat your oven to 325°F (163°C) with a rack in the middle. Lightly butter an 8-inch (20 cm) round cake pan or springform pan. For a regular pan, line the bottom with a circle of parchment paper, then butter the parchment as well.

Dust the inside of the pan with a thin layer of unsweetened cocoa powder, tapping out any excess. This prevents sticking and keeps the cake’s sides nicely chocolatey instead of floury or greasy.

Step 2: Melt the chocolate and butter

Place the chopped chocolate and 1/2 cup (115 g) butter in a heatproof bowl. Set the bowl over a saucepan of barely simmering water (do not let the bowl touch the water) to create a gentle double boiler. Stir occasionally until the chocolate and butter are completely melted and smooth.

Remove from heat and whisk in the vanilla extract, instant espresso powder (if using), and salt. Let this mixture cool for about 5 minutes so it is warm but not hot; this helps prevent scrambling the eggs later.

Alternatively, melt chocolate and butter in the microwave using 20–30 second bursts at medium power, stirring between each burst until silky smooth.

Step 3: Whip the eggs and sugar to a thick ribbon

In a large mixing bowl (or the bowl of a stand mixer), combine the 4 large eggs and 3/4 cup (150 g) granulated sugar. Beat on medium-high to high speed for 5–7 minutes, until the mixture is very thick, pale, and has nearly tripled in volume.

When you lift the beater, the egg mixture should fall back in a thick “ribbon” that slowly dissolves back into the surface. This step is key: it traps air that gives the cake its delicate crackly top and mousse-like interior despite having no flour or leavening.

Step 4: Combine the chocolate mixture with the eggs

With the mixer on low speed, slowly pour the warm (not hot) chocolate-butter mixture into the whipped eggs in a thin, steady stream. Take your time; this gradual addition helps keep the batter airy and prevents deflating the eggs too much.

Once all the chocolate is added, stop the mixer and sift the cocoa powder evenly over the surface of the batter. Using a large rubber spatula, gently fold the cocoa in with broad, sweeping motions, scraping the bottom and sides of the bowl. Fold just until no visible streaks remain. Overmixing here can knock out the air you just worked to build.

Step 5: Bake until set with a delicate crackly top

Pour the batter into the prepared pan and smooth the top with a spatula. Tap the pan gently once or twice on the counter to pop any large air bubbles, but do not overdo it.

Bake at 325°F (163°C) for 22–27 minutes, rotating the pan halfway through for even baking. The cake is done when:

The top is shiny, puffed, and has a thin, crackly crust.
The edges are set and slightly pulling away from the pan.
The center still has a gentle wobble when you nudge the pan, but does not look wet.

Do not overbake; a slightly underdone center is what creates that dense, mousse-like texture.

Step 6: Cool and unmold the cake

Transfer the pan to a wire rack and let the cake cool in the pan for 15 minutes. Run a thin knife around the edges to loosen. If using a springform pan, release the sides carefully. If using a regular pan, place a plate or cooling rack over the top of the pan and invert to release the cake, then peel off the parchment.

To serve right-side up, invert again onto a serving plate. Allow the cake to cool completely at room temperature, at least 1½ hours. As it cools, the center will settle into a rich, truffle-like texture while the top remains delicately crackly.

Step 7: Finish with powdered sugar and serve

Once the cake is fully cool (you can even chill it for 30–60 minutes for cleaner slices), use a fine-mesh sieve to dust the top generously with powdered sugar. The white sugar against the dark chocolate creates a beautiful contrast.

For neat slices, dip a thin, sharp knife in hot water, wipe it dry, and cut, wiping the blade clean between cuts. Serve the cake at room temperature or slightly chilled, with softly whipped cream and fresh berries if you like. The texture should be dense and silky in the center, like a baked chocolate mousse, with a whisper-thin crackly crust on top.

Pro Tips

Use good chocolate: Because there is no flour, the chocolate is the star. Choose a smooth, bittersweet bar (60–72% cacao) that you enjoy eating on its own.
Room-temperature eggs whip better: Cold eggs will not whip as voluminously. If needed, place whole eggs in warm tap water for 5–10 minutes before using.
Do not overbake: Pull the cake while the center still has a gentle jiggle. Overbaking leads to a dry, crumbly texture instead of a mousse-like one.
Fold gently: When combining the chocolate and cocoa with the whipped eggs, use light, sweeping motions to preserve as much air as possible.
Chill for ultra-clean slices: For picture-perfect presentation, chill the cake for 1–2 hours before slicing, then let the slices sit a few minutes at room temperature before serving.

Variations

Orange-Scented Flourless Chocolate Cake: Add 1 tbsp finely grated orange zest and 1–2 tbsp orange liqueur (such as Grand Marnier) to the melted chocolate and butter mixture. Garnish with orange zest curls.
Spiced Chili Chocolate Cake: Add 1/4 tsp ground cinnamon and a pinch (1/8–1/4 tsp) of cayenne pepper with the cocoa powder for a subtle, warming kick.
Mocha Lover’s Version: Increase instant espresso powder to 2 tsp and serve with coffee-infused whipped cream (add 1 tsp instant espresso dissolved in 1 tsp hot water to the cream).

Storage & Make-Ahead

Once completely cool, cover the cake tightly with plastic wrap or store in an airtight container. It keeps well at room temperature for up to 1 day and in the refrigerator for 4–5 days. For best texture, bring chilled cake slices to room temperature for 20–30 minutes before serving so the center softens slightly.

The cake also freezes beautifully. Wrap individual slices tightly in plastic wrap and then in foil, or place in a freezer-safe container. Freeze for up to 2 months. Thaw overnight in the refrigerator or at room temperature for about 1 hour before serving.

Nutrition (per serving)

Approximate values per slice (1 of 8): about 450 calories, 33 g fat, 36 g carbohydrates, 6 g protein, 26 g sugar, 3 g fiber, and 220 mg sodium. Actual nutrition will vary based on specific ingredients and portion sizes.

Flourless Bittersweet Chocolate Cake With Crackly Top