18-oz container whipped topping (or sub 2 cups of freshly whipped cream)
WHIPPED CREAM: (OPTIONAL)
1box graham crackers
Cocoa powder for garnish
To make the espresso custard:
It’s important to measure out all of your ingredients before you start, especially the egg yolks, just to ensure everything moves smoothly!
Combine sugar, espresso powder, flour, salt, and milk in a medium saucepan over medium heat. Whisk constantly until the sugar melts and the mixture is heated through but not boiling.
Pour about 1⁄4 cup of the mixture into the bowl with the egg yolks and quickly whisk together to temper them.
Add the egg yolk mixture back into the saucepan and reduce heat to medium-low. Whisk until the custard starts to thicken, which should happen soon after adding the eggs to the saucepan.
Once thick and resembles pudding consistency, remove from heat. Stir in vanilla. Place plastic wrap over the custard and carefully press it directly against the top of the custard. This will prevent the custard from developing a “skin” as it cools.
Store custard in the refrigerator for 4-6 hours (or overnight) or until completely cool. Once cool, fold in whipped topping. Store covered in the refrigerator until ready to use.
To make the espresso syrup:
Combine water and sugar in a small saucepan over medium-high heat. Bring mixture to a simmer, but don’t boil. Let mixture cook, stirring occasionally, for about 5 minutes or until slightly thickened and syrupy.
Stir in espresso powder and coffee liqueur. Store covered in the refrigerator until ready to use.
To make the chocolate ganache:
When you’re ready to decorate or serve the icebox cake, you can make the ganache and drizzle over the icebox cake. OR you can make it ahead of time and just reheat it until it’s drizzling consistency.
To make the ganache, heat cream in a small saucepan over medium heat until just beginning to bubble around the edges. Do not boil!
Pour hot cream over chocolate and let it sit for a few minutes. Stir or whisk until smooth. Drizzle over assembled icebox cake or store covered in the refrigerator until ready to use.
To make the whipped cream:
In the bowl of a stand mixer with the whisk attachment, whip cream, powdered sugar, and vanilla on medium-high speed until loose peaks form. You want them to be stiff at first, but not completely. They can be slightly soft on the top.
Use immediately or store covered in the refrigerator. You may need to give it a good stir with a whisk if it sits in the fridge for a bit.
Line an 8” x 4 ½” loaf pan with plastic wrap.
Start by breaking graham crackers in half to make squares. Dip graham crackers, one at a time, into the coffee syrup, quickly coating each side and letting the access drip off. Place one layer of syrup-soaked grahams into the bottom of the loaf pan, breaking grahams to fit the pan as needed.
Using a spoon or piping bag, add a layer of custard over the grahams. Repeat this process three more times (for four total layers of grahams and custard) or until the loaf pan is full. End with a final layer of grahams on the top.
Cover and freeze for 4 to 6 hours or overnight.
Once frozen (or when you’re ready to serve), lift icebox cake out of the pan by holding onto the plastic wrap or invert onto a plate or tray.
Drizzle ganache over the icebox cake, letting it drip down the sides. Wait a few minutes to let it set.
Pipe whipped cream over the ganache and dust with cocoa powder if desired.
Store loosely covered in the freezer. Thaw for 10 to 15 minutes before serving.