Summer Might Be Over But This No-Bake Cake Is Still Everyone’s Favorite Dessert

This no-bake, easy chocolate eclair cake is an elegant dessert you can easily make from scratch using a few simple everyday ingredients! With layers of crunchy graham crackers, homemade diplomat cream, and decadent chocolate ganache to finish, it is simple enough to indulge in at home yet impressive enough to serve on special occasions.

Best From-Scratch Chocolate Eclair Cake Recipe

If you're tired of the same boring cookie-cutter recipes for chocolate éclair cake, you've come to the right place! The homemade diplomat cream and chocolate ganache are what truly elevate this chocolate éclair cake. Homemade diplomat cream combines the best of both worlds: the smooth richness of pastry cream with the lightness of whipped cream. This cream is far superior to any store-bought or pre-made filling.

The homemade chocolate ganache brings out a richer, more authentic chocolate flavor. Plus, it hardens to a perfect, shiny layer that looks professional and contrasts beautifully with the light diplomat cream.

My simple no bake chocolate eclair cake is a breeze to assemble and customize, even if you're new to making desserts from scratch. I've also included plenty of expert tips and information to help you avoid mishaps and achieve the best results the first time around. The hardest part is waiting for it to chill!

Ingredients

You only need a few simple pantry staples, such as graham crackers, egg, sugar, milk, vanilla, and of course, chocolate to make this recipe. For a printable recipe card with exact ingredient quantities, visit the original Chocolate eclair cake recipe at Spatula Desserts.

Luxurious Diplomat Cream Will Take Your Chocolate Eclair Cake to the Next Level

To make the diplomat cream, we'll begin with a classic pastry cream. First, the butter must be softened to give you a smooth, creamy result. Use unsalted butter to avoid added salt.

Whisk the sugar and egg yolks in a mixing bowl for 1–2 minutes until the mixture turns light and fluffy. Then stir in the cornstarch, flour, and vanilla extract until smooth.

Heat the milk over medium heat in a saucepan until it starts to simmer. Do not let it reach a boil. Once it starts to simmer, slowly pour the mixture into the egg mixture, whisking constantly to prevent the eggs from scrambling.

Pour the mixture back into the saucepan and continue to cook over medium heat, stirring constantly until the cream thickens (about a minute after it starts to bubble). If it looks lumpy, keep whisking until it smooths out. Remove it from the heat and run it through a strainer if necessary.

Gradually add the softened butter, one chunk at a time, ensuring each portion is fully blended before adding the next. Once thoroughly incorporated, cover the cream with plastic wrap and let it cool to room temperature.

In the meantime, prepare your 9x13-inch / 22x33cm baking dish and Graham crackers.

Once the cream has cooled, add the cold heavy cream to a medium bowl and whip it using an electric hand mixer for 2–3 minutes until soft peaks form. Don't overmix, or it will become runny. You want it to be nice and fluffy and just enough voluminous so that you can fold it together with the pastry cream.

Loosen your pastry cream with a few quick whisks, then gently fold in the whipped cream using a rubber spatula. Please do not use your electric mixer at this point, as we want to fold the two creams together, not mix. You want to keep the final cream light and fluffy. I recommend folding in the heavy cream in stages and adding more after each fold.

Let's Assemble

Divide the graham crackers (or digestive biscuits, if you prefer) into three portions, one for each layer. Next, divide the diplomat cream into two portions for the two layers between the graham crackers.

Place the first third of the graham crackers in a single, even layer at the bottom of the pan. You may need to break the crackers to cover the whole surface. Evenly spread half of the diplomat cream over the graham crackers. Then, place the second layer of graham crackers on top, followed by the remaining diplomat cream. Finish it off with the final layer of graham crackers on top.

Once it's all layered, place the pan in the fridge while you prepare the chocolate ganache.

Finally, Top The Cake With Chocolate Ganache

We'll coat the chocolate eclair cake with ganache for the finishing touch. First, partially melt your chocolate (preferably semi sweet chocolate) in the microwave. I recommend heating it in increments and using a plastic bowl, as glass bowls tend to heat up too quickly and burn the chocolate.

Meanwhile, heat the heavy cream in a saucepan until it begins to simmer. Pour the simmering cream over the semi-melted chocolate and stir until it becomes nice and smooth. Then, stir in the oil.

making the Chocolate Ganache for the boston cream cake.

Set the glaze aside until it cools to approximately 30°C (86°F). It should have a smooth consistency that isn't too runny and not too thick.

Pour the chocolate ganache over the top of the cake and use a spatula to smooth it out. Let the cake chill for at least 4 hours to allow the layers to soften. Then, serve and enjoy!

How to Store

If you have leftovers, you can store them covered in the refrigerator for up to two days. The layers will continue to soften over time.

I do not recommend freezing chocolate eclair cake, as the frozen whipped topping becomes grainy and less flavorful once thawed.

Expert Tips For Making Chocolate Eclair Cake

Choose full-fat ingredients for the best flavor and texture of your diplomat cream and chocolate ganache. Low-fat options have a higher water content, which results in a runnier consistency. I recommend using whole milk with 3% fat, European-style butter with 82% fat, and heavy cream with at least 36% fat. Always choose pure vanilla extract or vanilla bean paste– never imitation!
Refer to my guide on softening butter quickly for tips on doing so without a microwave.
Opt for high-quality chocolate, such as Callebaut, Ghirardelli, or Lindt, when making the ganache (never use imitation chocolate). If using bars, chop the chocolate finely before melting so it blends evenly.
Transfer the pastry cream to a shallow bowl or cake pan to cool it more quickly. Make sure the plastic wrap touches the surface to prevent skin from forming.
If the cream still feels soft, let it chill in the fridge for another 1 to 2 hours before using. If it is still hard, continue to whisk it vigorously using a hand whisk to help loosen it up.

Useful Equipment

Use a digital scale to weigh your ingredients for the most accurate results and best outcome. A digital thermometer will be handy to ensure the chocolate glaze cools to the right temperature before applying it to the cake.

You will need an electric hand mixer to make the pastry cream portion of the diplomat cream and a rubber spatula to gently fold in the whipping cream while keeping it light and fluffy.

A 9x13-inch baking pan is necessary for assembling, and a piping bag can help make fun decorations!

If you loved making this easy recipe for chocolate eclair cake, make sure you try my other delicious sheet cake recipes:

And for even more decadent no-bake desserts and cakes, check out my roundup of the Top 35 Best No-Bake Desserts!