Indulge in the ultimate chocolate lover’s dream, made keto! These Decadent Keto Chocolate Mousse Brownies feature a rich, fudgy keto brownie base topped with a light, airy, and intensely chocolatey sugar-free mousse. It’s a luxurious two-layered dessert perfect for satisfying serious chocolate cravings the low-carb way. Pure chocolate bliss in every bite!
Yields: 12 servings
Prep time: 30 minutes
Cook time: 25-35 minutes (brownie)
Chill time: 6+ hours
Total time: Approx. 7 hours 15 minutes (includes cooling & chilling)
Course: Dessert
Cuisine: American
Method: Baking, Stovetop (for mousse prep)
Equipment:
- 9×13 inch baking pan (or 8×8 / 9×9 for thicker layers – See Note 1)
- Parchment paper
- Mixing bowls (large, medium, small)
- Electric mixer (handheld or stand)
- Heatproof bowl (for melting chocolate)
- Small saucepan (for mousse cream/gelatin)
- Whisk
- Rubber spatula
- Offset spatula or knife for spreading mousse
- Sifter (optional, for cocoa/flour)
Ingredients:
Keto Brownie Layer:
- 2 Tbsp unsalted butter, softened (for greasing pan)
- 8 ounces (226g / 2 sticks) unsalted butter, melted
- 4 large eggs, room temperature
- 1 3/4 cups (approx. 330-350g) granulated low-carb sweetener (e.g., erythritol, allulose blend – adjust to taste)
- 1 1/4 cups (110g) unsweetened cocoa powder, sifted
- 1 tsp vanilla extract
- 1/2 cup (56g) fine almond flour, sifted (replaces AP flour)
- 1/2 tsp kosher salt
Keto Chocolate Mousse:
- 10 ounces (approx. 283g) sugar-free milk chocolate style chips or finely chopped bar (e.g., Lily’s, ChocZero) – See Note 2
- 2 1/2 cups (600ml) heavy whipping cream, chilled, divided
- 1 packet (7g or approx. 2.25 tsp) unflavored gelatin
- 2 Tbsp (30ml) cold water
Garnish (Optional):
- Unsweetened cocoa powder
- Sugar-free chocolate shavings
Ingredient Notes:
- Pan Size: Using a 9×13 inch pan results in thinner brownie and mousse layers, similar to the original recipe photo likely. For thicker, more substantial layers, use an 8×8 inch or 9×9 inch square pan. Remember to adjust the brownie baking time if using a smaller pan (it will likely need closer to 30-35+ minutes).
- Chocolate Type: Sugar-free milk chocolate style chocolate (like Lily’s or ChocZero) yields a mousse flavor closer to the original recipe. If you prefer or only have sugar-free dark chocolate (like 70%+ cocoa), use that instead. You may want to add 1-2 tablespoons of powdered low-carb sweetener to the whipped cream (in step 9) to balance the bitterness, adjusting to your personal taste.
Instructions:
- Prep for Brownie: Preheat oven to 325°F (160°C). Line your chosen baking pan (9×13, 9×9, or 8×8) with parchment paper, ensuring there is an overhang on at least two opposite sides for easy removal later. Grease the parchment paper and any exposed sides of the pan well with the 2 Tbsp softened butter.
- Make Brownie Batter:
- In a large bowl using an electric mixer fitted with the whisk attachment (or a handheld mixer), beat the 4 room-temperature eggs on medium speed until they are light yellow, significantly increased in volume, and fluffy (this takes about 2-3 minutes).
- Gradually beat in the granulated low-carb sweetener until fully combined.
- Switch to a paddle attachment or use a rubber spatula. Gently stir in the 8 oz of melted (and slightly cooled) butter until incorporated.
- Add the sifted cocoa powder, 1 tsp vanilla extract, and 1/2 tsp salt. Stir on low speed or by hand until just combined.
- Gently stir in the sifted almond flour until just incorporated. Be careful not to overmix the batter at this stage. The batter will be thick and fudgy.
- Bake Brownie Layer: Spread the brownie batter evenly into the prepared pan using an offset spatula or the back of a spoon. Bake in the preheated oven for 25-35 minutes (check earlier for smaller pans). The brownie is done when the edges are set and a wooden skewer or toothpick inserted into the center comes out with moist, fudgy crumbs attached, but no wet batter. Avoid overbaking for a fudgy texture.
- Cool Brownie Completely: Remove the pan from the oven and place it on a wire cooling rack. Let the brownie cool completely within the pan. This is crucial for the structure and before adding the mousse layer (allow at least 1-2 hours, or until no longer warm to the touch).
- Prepare Mousse Components:
- If using a bar, finely chop the 10 oz of sugar-free chocolate. Place the chopped chocolate or chips in a medium-sized heatproof bowl.
- In a separate small bowl, sprinkle the unflavored gelatin evenly over the 2 Tbsp cold water. Let it sit undisturbed for 5-10 minutes to bloom (it will absorb the water and become thick and jelly-like).
- Melt the sugar-free chocolate until smooth. You can use a double boiler (place the heatproof bowl over a saucepan with 1-2 inches of gently simmering water, ensuring the bottom of the bowl doesn’t touch the water) or microwave carefully (heat in 20-30 second intervals at 50% power, stirring well after each, until just melted and smooth). Set the melted chocolate aside briefly while you heat the cream.
- Heat Cream & Dissolve Gelatin: Pour 1/2 cup of the heavy cream into a small saucepan. Heat over medium-low heat just until bubbles form around the edges and it’s steaming (do not let it boil vigorously). Remove the pan from the heat immediately. Add the bloomed gelatin mixture to the hot cream and stir or whisk constantly until the gelatin is completely dissolved and the mixture is smooth.
- Combine Chocolate Ganache: Pour about half of the hot cream/gelatin mixture over the melted chocolate. Whisk quickly and vigorously starting from the center and working outwards until the mixture starts to combine and emulsify. Add the remaining hot cream mixture and continue whisking until the ganache is completely smooth, glossy, and homogenous.
- Cool Ganache: Let the chocolate ganache mixture cool completely to room temperature. This is important – if it’s warm, it will melt the whipped cream. Stir it occasionally as it cools to keep it smooth and prevent a skin from forming (this might take 30-45 minutes).
- Whip Remaining Cream: While the ganache is cooling, pour the remaining 2 cups of cold heavy whipping cream into the clean bowl of a stand mixer fitted with the whisk attachment (or use a large chilled bowl and hand mixer). Beat on medium-high speed until soft peaks form (the peaks should just start to hold their shape but curl over softly at the tip when the beaters are lifted). Be careful not to overwhip at this stage. Optional: If using dark chocolate and desire a sweeter mousse, you can add 1-2 Tbsp of powdered low-carb sweetener here and beat briefly to combine.
- Fold Mousse: Once the chocolate ganache is definitely at room temperature (cool to the touch), gently fold it into the whipped cream. Add the ganache in about three separate additions, using a large rubber spatula to fold carefully after each addition (using an upward over-and-down motion) until just combined and no streaks of chocolate or white remain. Be gentle to maintain as much air and volume from the whipped cream as possible.
- Assemble: Pour the finished chocolate mousse evenly over the completely cooled brownie base still in the pan. Use an offset spatula or the back of a spoon to smooth the top layer evenly.
- Chill Thoroughly: Cover the pan tightly with plastic wrap or foil (try not to let it touch the mousse surface if possible). Refrigerate for at least 6 hours, or preferably overnight, until the mousse is completely firm and fully set.
- Slice and Serve: Once fully chilled and set, use the parchment paper overhangs to carefully lift the entire brownie/mousse block out of the pan onto a sturdy cutting board. If desired, dust the top lightly with unsweetened cocoa powder or sprinkle with sugar-free chocolate shavings for garnish. For the cleanest slices, use a large, sharp knife dipped in hot water and wiped dry between each cut. Cut into 12 equal squares (or your desired serving size).
- Serve: Serve the brownies chilled. Store any leftovers tightly covered in the refrigerator for up to 5 days.
Estimated Nutritional Information:
Disclaimer: Nutritional information is an estimate calculated using standard nutritional databases for the ingredients listed (almond flour, cocoa, butter, heavy cream, eggs, erythritol/allulose-based sweeteners, SF milk chocolate style chips/bars, gelatin). Actual values will vary based on specific brands used (especially sugar-free chocolate and sweeteners), ingredient choices, potential substitutions, and exact portion sizes. This is a very rich, calorie-dense keto dessert.
Per Serving (1/12th of recipe):
- Calories: approx. 575 kcal
- Total Fat: approx. 55.5g
- Saturated Fat: approx. 32g
- Total Carbohydrates: approx. 44.5g (Includes fiber & sugar alcohols)
- Dietary Fiber: approx. 3.5g
- Sugar Alcohols: approx. 36g (Primarily from sweeteners & SF chocolate)
- Net Carbohydrates: approx. 5g (Total Carbs – Fiber – Sugar Alcohols)
- Protein: approx. 9.5g
- Sodium: approx. 130mg
(Note: Net carbs are calculated by subtracting fiber and applicable sugar alcohols like erythritol or allulose. Individual responses to sweeteners and sugar-free chocolates can vary. Verify ingredients fit your dietary needs.)
