Chocolate Eclair Cake

5 from 1 vote

Featuring layers of crunchy graham crackers, homemade diplomat cream, and decadent chocolate ganache, this no-bake, easy chocolate eclair cake is a simple yet elegant recipe perfect for any occasion!

Prep Time30

Chilling time4

Total Time4 30

Course: Dessert

Cuisine: American

Servings:

Calories: 635kcal

Author: Katalin Nagy

Equipment

Ingredients

Diplomat Cream

960 g Whole milk 3% fat
200 g Granulated sugar
160 g Egg yolk approximate yolk of 8 eggs
50 g Corn starch
50 g All purpose flour
½ tablespoon Vanilla extract
110 g Unsalted butter 82% fat, at room temperature
230 g Heavy cream 36% fat content, cold

Chocolate ganache

230 g Semi-sweet chocolate
230 g Heavy cream 36% fat content
1 tablespoon Vegetable oil

To assemble

14 oz Graham cracker 1 package, 400g. Can be substituted with an equal amount of Digestive biscuits.

Metric - US Customary

Instructions

Diplomat cream

Start with making a basic pastry cream: whisk the sugar and egg yolks together in a bowl for 1-2 minutes until the mixture is light and fluffy. Then, add the cornstarch, flour, and vanilla, and mix until the mixture is smooth.
In a saucepan, heat the milk over medium heat until it starts to simmer (but not boil). Slowly pour the hot milk into the egg yolk mixture, whisking constantly to temper the yolks.
Return the mixture to the saucepan and cook over medium heat, stirring continuously, until it thickens—this should take about a minute after boiling. If the mixture is lumpy, keep whisking until smooth. Remove from heat and strain if necessary.
Gradually add the softened butter, mixing until fully incorporated.
Cover the pastry cream with plastic wrap and let it come to room temperature while preparing a 9x13 / 22x33cm baking dish and your Graham crackers.
Once the cream is cooled to room temperature, place very cold 36% fat-content heavy cream in a mixing bowl and use an electric hand mixer to whip the mixture for about 2-3 minutes until fluffy. Do not overwhip.
Gently loosen the pastry cream with a few quick whisks, then carefully, using a rubber spatula, fold in the whipped heavy cream, ensuring the mixture stays light and airy.

Assemble

To assemble, divide the graham crackers into 3 (as there will be three layers) and the diplomat cream into 2 (as there will be two layers).
Place one-third of the graham crackers in a single, tight layer at the bottom of a 9x13-inch baking pan. Break the crackers as necessary to fit. Evenly spread half of the diplomat cream on top. Add a second layer of graham crackers on top of this. Then, spread the remaining diplomat cream. Finally, top with a third layer of graham crackers.
Refrigerate while preparing the chocolate ganache glaze.

Chocolate ganache glaze

Semi-melt the chocolate in the microwave. Meanwhile, heat the cream in a saucepan until it just begins to simmer. Pour the simmering cream over the melted chocolate and stir until smooth, then stir in the oil. Set aside and allow the glaze to cool to about 30°C (86°F). It should have a smooth consistency—neither too runny nor too thick—before spreading it all over the cake.
Pour the chocolate ganache glaze over the cake and smooth with a spatula. Chill the cake for 4 hours before serving, for the layers to soften.
Serve the Chocolate eclair cake after the 4 hours of chilling time. Any leftovers can be covered and stored in the refrigerator for 2 days. The layers will further soften over time.

Notes

Ingredient notes:

Measure your ingredients with a digital scale for accuracy.
Graham crackers can be substituted with digestive biscuits, ladyfingers, Biscoff cookies, or similar not-too-hard, not-too-soft biscuits.
Good quality butter and pure vanilla extract are the heart of making pastry cream. Use high-quality 82% fat-content European butter and the best quality vanilla you can access.
For the whipped cream, high-fat (36%) heavy cream is recommended, and it should be used very cold. Cream with a lower fat content might not whip up properly.

Technique notes:

Use a small/medium-sized saucepan with good heat distribution to avoid burning the milk when making pastry cream.
Whipped cream frosting is very easy to overwhip. When whipping, stop as soon as the mixture has reached a fluffy consistency and stiff peaks. It won't get stiffer after this point. In fact, if you overbeat it, it will only get runnier, and then it will break.
Pay attention to the equipment mentioned in the recipe, when to use a mixer, and when to use the rubber spatula.
The cake will soften over time. I personally like it on the first day, as it can get a bit too moist after that.

Nutrition