French silk slab pie gives you a whole tray of chocolate pie squares with a flaky pastry base, an airy chocolate filling, and whipped cream on top. The filling is rich, but the shallow sheet-pan shape keeps the portions manageable. A few chocolate curls finish it without much decorating.
The useful thing to know before starting is that this pie comes together in stages. The crust must cool, the cooked chocolate mixture needs time to lose its heat, and the filled pie has to chill before you slice it. Leave room for those pauses and the assembly is much easier.
Give the cooling steps room in your schedule
Use a rimmed half-sheet pan, approximately 18 × 13 inches. This is a shallow slab pie, so the pastry and filling spread over a much wider area than they would in a round pie dish.
Plan on a few hours from start to serving, including the 1–2-hour chilling step. The times in the recipe card are planning estimates, and a warm kitchen or a filling that needs longer to set can extend them. Get the crust into the oven first, then work on the filling while it cools.
Let the baked crust cool completely before filling it. The chocolate mixture also needs to be barely warm before you beat it into the butter. After assembly, chill the pie until the filling is firm enough to slice.
Start with the pastry shell
The recipe uses two softened 9-inch pie crusts. Stack them and roll them together into a rectangle slightly larger than the pan. Ease the pastry into the corners rather than stretching it, then trim and shape the low edge.
Line the pastry with parchment and add pie weights or dried beans. Begin with the recipe’s 15–17-minute bake at 350°F, then remove the weights and check the base. If it still looks pale or damp, continue baking without the weights until it is lightly golden and dry. The filling won’t go back into the oven, so the pastry needs to be fully baked now.
Let the shell cool completely in the pan. Adding filling to a warm shell can soften the chocolate layer before it has a chance to set.
Build the silk filling in two parts
First comes the cooked chocolate base. Choose bittersweet chocolate for the filling and reserve a little extra chocolate for the top. Melt it in short microwave intervals, stirring between each one so the last small pieces melt into the warm chocolate.
Whisk the eggs and granulated sugar together in a saucepan over low heat. Keep the whisk moving across the bottom and corners. Cook until the sugar dissolves and the mixture reaches 160°F on a thermometer; the suggested 5 minutes is a guide, not the final check.
Take the saucepan off the heat and stir in the melted chocolate and vanilla. The mixture should be smooth before you let it cool, with an occasional stir as it stands.
The second part is the butter. Use softened unsalted butter, not melted butter, and beat it until lighter and fluffy. Add the chocolate mixture slowly once it is only barely warm, then beat until the filling looks lighter. Hot chocolate mixture can melt the butter and undo that whipped texture.
One batch of cream does two jobs
Start with cold heavy whipping cream, then add the powdered sugar as the cream begins to thicken. Beat until the peaks stand when the beaters are lifted. Stop there; the cream should still look smooth.
Measure 1½ cups of the already-whipped cream and fold that portion into the chocolate filling. That measurement is for prepared whipped cream, not liquid cream. Use a gentle folding motion until the color is even, and keep the rest of the whipped cream chilled for the topping.
Spread the finished filling across the cold pastry shell, working it gently toward the corners. Level it with a spatula so the squares will have an even chocolate layer.
Let it set before adding the finish
Refrigerate the filled crust for 1–2 hours, or longer if the filling is still too soft to slice. The chilled filling should hold its shape; adding the cream topping won’t make a loose chocolate layer firmer.
Once it has set, spread or pipe the reserved whipped cream over the pie. Loose spatula swoops are an easy finish for a slab pie. Add chocolate curls or shavings just before serving.
Cut for the table you’re serving
For about 24 squares, cut the slab into six columns and four rows. That yield is approximate, and you can cut smaller pieces when this is one of several desserts. Use a sharp knife and wipe it between cuts so whipped cream doesn’t drag across the chocolate edges.
Lift each square from underneath with a thin spatula. A few flakes from the pastry are normal; the goal is to keep the soft layers supported as you move the piece to its plate.
For another dessert with chocolate and a creamy center, try Boston Cream Poke Cake. If you prefer a cinnamon-topped tray dessert, Sopapilla Cheesecake is another option.
A few details worth clearing up
Is this a no-bake pie? The filling doesn’t bake in the oven, but the pastry does, and the egg mixture cooks on the stovetop. Both steps are part of this version.
Can I use a smaller baking dish? A smaller dish will make deeper layers and change the way the crust fits and the filling chills. The instructions here are written for the shallow half-sheet pan.
Why does the filling look loose? Check that the chocolate mixture cooled before it was beaten into the butter, the cream reached standing peaks, and the assembled pie had enough chilling time. Those stages give the filling its structure.
French Silk Slab Pie
Equipment
- Rimmed half-sheet pan (about 18 × 13 inches)
- Rolling Pin
- Parchment paper and pie weights
- Medium saucepan
- Food thermometer
- Electric mixer and mixing bowls
- Spatula
Ingredients
Pastry crust
- 2 9-inch pie crusts softened
Chocolate filling
- 10 oz bittersweet chocolate plus additional chocolate for garnish
- 4 large eggs
- 1 1/3 cups granulated sugar
- 2 teaspoons vanilla extract
- 1/2 cup unsalted butter 1 stick, softened
Whipped cream for filling and topping
- 2 1/2 cups heavy whipping cream
- 1/3 cup powdered sugar
Instructions
Bake and cool the pastry
- Preheat the oven to 350°F. Lightly coat a half sheet pan with nonstick cooking spray and set it aside.
- Place the two softened pie crusts on a lightly floured work surface, stacking one over the other. Roll them together into a rectangle slightly larger than the sheet pan.
- Carefully transfer the rolled dough to the prepared pan. Press it gently across the bottom and into the corners, trim away any excess dough, then crimp or shape the edges as desired.
- Cover the pastry with parchment paper and fill it with pie weights or dried beans. Bake at 350°F for 15–17 minutes, then carefully remove the weights and parchment. If the base is still pale or damp, continue baking without the weights until it is lightly golden, dry, and fully baked.
- Allow the fully baked pastry crust to cool completely in the pan before adding the filling.
Make the chocolate filling
- Place the bittersweet chocolate in a microwave-safe bowl. Microwave in 30-second intervals, stirring after each interval, until almost completely melted. Continue stirring until smooth, then set aside.
- Whisk the eggs and granulated sugar together in a medium saucepan. Cook over low heat, stirring constantly, until the sugar dissolves and the mixture reaches 160°F (71°C) on a thermometer. About 5 minutes is a guide; use the temperature as the deciding check.
- Remove the saucepan from the heat. Stir in the melted chocolate and vanilla until the mixture is completely smooth, then allow it to cool until warm, stirring occasionally.
- Place the softened butter in a large mixing bowl and beat with an electric mixer for 2-3 minutes, or until noticeably lighter and fluffy.
- Slowly pour the cooled chocolate mixture into the whipped butter while mixing. Once incorporated, increase the mixer speed and beat for about 5 minutes, until the filling becomes lighter and fluffy.
Whip, fill and finish
- In a separate mixing bowl, beat the heavy whipping cream until it begins to thicken. Add the powdered sugar and continue beating until stiff peaks form.
- Measure 1 1/2 cups of the already-whipped cream and gently fold it into the chocolate mixture until evenly incorporated. Keep the remaining whipped cream refrigerated for the topping.
- Spoon the French silk filling into the completely cooled pastry crust and spread it into an even layer.
- Refrigerate the slab pie for 1-2 hours, or until the chocolate filling is properly set.
- Spread or pipe the reserved whipped cream over the chilled chocolate filling. Finish with chocolate curls or shavings, slice into squares, and serve cold.
Notes
- The ingredient quantities are for a shallow rimmed half-sheet pan, approximately 18 × 13 inches.
- The pastry must be fully baked and completely cooled before filling.
- Let the cooked chocolate mixture cool until only barely warm before beating it into the softened butter.
- Measure 1½ cups after whipping the cream for folding into the filling. Keep the remaining whipped cream chilled for the topping.
- Chill the filled crust for 1–2 hours, or longer if needed, until the filling holds its shape.
- Times are planning estimates. The total includes a 2-hour chilling allowance; cooling and setting may take longer.
- For approximately 24 squares, cut six columns and four rows. Yield depends on portion size.