Decadent Chocolate Espresso Mousse Squares

1. Prep the Pan

Line a 9-inch-by-13-inch baking pan with parchment paper, ensuring it covers the bottom and sides for easy removal later.

2. Make Graham Cracker Crumbs

Place the graham crackers in a food processor and pulse until they turn into fine crumbs. If you don't have a food processor, you can place the crackers in a resealable plastic bag and crush them with a rolling pin.

3. Prepare the Crust

Transfer the graham cracker crumbs to a medium bowl and stir in the melted butter, granulated sugar, and 0.25 teaspoon kosher salt. Mix until the crumbs are evenly coated and resemble wet sand. Pour the crumb mixture into the prepared baking pan, pressing it firmly into an even layer to create a solid crust. Place the crust in the freezer while you prepare the filling.

4. Heat Cream and Dissolve Espresso Powder

In a small saucepan, heat 1 cup of heavy cream with the instant espresso powder and 0.5 teaspoon kosher salt until the cream is hot but not boiling. This step ensures the espresso powder dissolves completely and infuses the cream with a rich coffee flavor.

5. Melt Chocolate

Pour the hot cream over the finely chopped semisweet chocolate in a medium bowl and let it stand for two minutes. Then, add the vanilla extract and whisk until the chocolate mixture is smooth and glossy. Allow it to cool completely.

6. Whip Cream

While the chocolate mixture is cooling, whip 2 cups of cold heavy cream in a large bowl or stand mixer fitted with a whisk attachment until stiff peaks form.

7. Fold Chocolate into Whipped Cream

Gently fold the cooled chocolate mixture into the whipped cream until no streaks remain, creating a light and airy mousse.

8. Assemble Mousse Squares

Retrieve the crust from the freezer and pour the mousse over it, spreading it into an even layer. Cover the pan and refrigerate for at least 2 hours, allowing the mousse to set.

9. Serve

Once chilled, cut the mousse into squares using a sharp knife. If desired, top each square with a dollop of whipped cream before serving.