Keto Chocolate Eclair Cake

Traditional eclairs were always one of my favorite bakery treats to pick up on the weekend.

When I switched to eating low carb, I thought I would have to give up that classic mix of pastry, rich vanilla cream, and chocolate.

That is why I created this keto chocolate eclair cake, which gives you all of those familiar flavors without the sugar crash.

It is completely keto friendly and fits nicely into your daily carb limits while still tasting like a real bakery dessert.

You simply bake the soft cake base, layer it with a thick vanilla filling, and top it with smooth chocolate ganache.

Why You’ll Love This Recipe

Bakery Quality Taste – You get the authentic flavor of a classic French pastry without all the sugar and carbs.

Luxurious Cream Filling – Mascarpone and heavy cream create an ultra-rich filling that tastes just like traditional pastry cream.

Decadent Chocolate Ganache – Real sugar-free dark chocolate melts into heavy cream for a glossy top layer that looks bakery-fresh.

Tender Cake Texture – Almond and coconut flour create light, soft sponge layers that slice effortlessly like real choux pastry.

Recipe Ingredients

For the Cake Layers

• 2 cups Superfine Blanched Almond Flour
• 3 tbsp Coconut Flour
• 2/3 cup Granulated Erythritol Monk Fruit Sweetener
• 2 1/2 tsp Baking Powder
• 1/2 tsp Xanthan Gum
• 1/4 tsp Salt
• 6 tbsp Unsalted Butter, Melted
• 4 large Eggs, Room Temperature
• 1/3 cup Full-Fat Sour Cream
• 1/4 cup Unsweetened Almond Milk
• 2 tsp Vanilla Extract

For the Vanilla Cream

• 8 oz Mascarpone Cheese, Cold
• 1 3/4 cups Heavy Whipping Cream, Cold
• 2/3 cup Powdered Erythritol Monk Fruit Sweetener
• 1 tbsp Vanilla Extract

For the Chocolate Ganache

• 4 oz Sugar-Free Dark Chocolate Chips
• 1/2 cup Heavy Whipping Cream
• 1 tbsp Unsalted Butter

How To Make

Step 1

Preheat the oven to 325°F (165°C). Line a 9×13-inch baking pan with parchment paper, leaving an overhang on the long sides so the cake can be lifted out easily.

Step 2

In a large bowl, whisk together the almond flour, coconut flour, granulated sweetener, baking powder, xanthan gum and salt. Add the melted butter, eggs, sour cream, almond milk and vanilla extract and mix until smooth.

Step 3

Spread the batter evenly in the pan and bake for 20-24 minutes, until golden and set in the center. Cool completely in the pan.

Lift the cake out using the parchment and cut it in half crosswise to make two equal rectangles.

Step 4

For the vanilla cream, add the cold mascarpone, cold heavy cream, powdered sweetener and vanilla extract to a large bowl. Beat on low for 30 seconds, then on medium-high for 2-3 minutes until thick, stiff peaks form.

Step 5

Place one cake rectangle on a serving platter and spread all of the vanilla cream over it in a thick, even layer. Gently set the second rectangle on top and refrigerate for 30 minutes.

Step 6

For the ganache, heat the heavy cream until just simmering and pour it over the chocolate chips and butter. Let it sit for 2 minutes, then stir until smooth and glossy. Cool for about 10 minutes, until thickened but still spreadable.

Step 7

Spread the ganache over the top of the cake. Refrigerate for at least 4 hours, or overnight, so the layers soften slightly and slice cleanly like a real eclair.

Tips

Let the Cake Cool Completely Before Cutting

Almond flour cakes are very delicate while they are still warm. If you try to lift or slice the cake right out of the oven, it will crumble apart.

I recommend leaving the cake in the pan on the counter until it reaches room temperature.

Once it is completely cool, the ingredients firm up and give the cake the solid structure it needs to hold together when you cut it in half.

Watch the Cream Closely While Whipping

Mascarpone cheese has a very high fat content and can split or turn watery if you beat it for too long.

Keep both the mascarpone and the heavy whipping cream in the fridge until the exact second you are ready to mix them.

From my experience, you should stop your mixer the moment you see stiff peaks hold their shape. Going even thirty seconds too long can make your filling grainy instead of silky.

Always Use Powdered Sweetener for the Filling

Granulated erythritol does not dissolve well in cold dairy. If you use granular sweetener in the cream filling, your dessert will end up with an unpleasant crunchy grit.

You will get the best results if you use a confectioners or powdered blend.

If you only have granular sweetener on hand, my favorite trick is to buzz it in a clean blender for a few seconds until it turns into a fine powder before adding it to the bowl.

More Recipes

• Keto Boston Cream Pie Cupcakes
• Keto Chocolate Ganache Tart
• Keto Cream Puffs
• Keto Death by Chocolate Trifle
• Keto Vanilla Bean Custard Cups

Frequently Asked Questions

Can I use regular cream cheese instead of mascarpone?

Yes, you can substitute full-fat block cream cheese in an equal amount, but make sure to soften it slightly first so it blends smoothly without lumps.

Keep in mind that cream cheese has a tangier flavor than rich, mild mascarpone, so the filling will taste a bit more like cheesecake.