One-Pot Strawberry Rhubarb Custard Éclair Bars

Steps

1. 1

   Make the choux base

   • In a medium saucepan, combine the cold butter cubes, water, and salt.
   • Set over medium heat and stir occasionally with a wooden spoon until the butter melts completely and the mixture comes to a full boil—you should see bubbling across the entire surface.
   • Remove from heat and stir in the flour until a thick, smooth paste forms.
   • Let cool for about 2 minutes, then beat in the eggs one at a time, stirring vigorously after each addition until fully incorporated.
   • The batter should be smooth, thick, and glossy.

   + Show details− Hide details

   Ready when: Mixture is smooth and glossy after eggs are fully beaten in

   Tip: Don't skip cooling the roux before adding eggs, or they may scramble. Stir vigorously to ensure eggs are fully incorporated—this creates the structure for puffing.

2. 2

   Spread choux and bakeOven 400°F / 205°C

   • Spread the choux batter evenly onto the prepared 9×13-inch baking sheet—it should be about ¼ inch (6 mm) thick.
   • Use an offset spatula or the back of a wet spoon to smooth the top.
   • Place in the preheated 400°F (200°C) oven and bake for 25–28 minutes, until the pastry is puffed, golden brown, and firm to the touch.
   • The edges should be darker than the center.
   • Remove from the oven and let cool on the baking sheet while you prepare the compote and custard.

   + Show details− Hide details

   Ready when: Pastry is puffed, golden brown, and feels firm and crisp when touched

   Tip: Don't open the oven door during the first 20 minutes—moisture can escape and prevent proper puffing. If the pastry seems too pale after 25 minutes, bake another 2–3 minutes.

3. 3

   Prepare the strawberry-rhubarb compote

   • While the choux bakes, combine the halved strawberries, rhubarb pieces, sugar, and lemon juice in a small saucepan.
   • Bring to a gentle simmer over medium-low heat, stirring occasionally.
   • Cook for 8–10 minutes until the rhubarb breaks down and the mixture thickens slightly—it should release its juices and reduce by about a third.
   • The fruit should still have some structure (not completely smooth).
   • Remove from heat and let cool to room temperature.

   + Show details− Hide details

   Ready when: Mixture is thickened and fruit pieces are soft but still slightly chunky

   Tip: Don't overcook the compote or it will become jammy and lose its fresh fruit flavor. If using frozen strawberries, thaw them first and reduce sugar slightly to account for their juice.

4. 4

   Make the custard fillingOven 160°F / 70°C

   • In a medium bowl, whisk together the egg yolks, sugar, cornstarch, and salt until the mixture is pale and thick, about 1 minute.
   • Slowly pour the milk into the egg mixture while whisking constantly to prevent lumps.
   • Pour this mixture into the same small saucepan you used for the compote (rinse if needed) and place over medium heat.
   • Cook, stirring constantly with a whisk, for 5–7 minutes until the custard thickens noticeably and coats the back of a spoon.
   • The mixture should reach 160°F (71°C) if using a thermometer, ensuring the eggs are safely cooked.
   • Remove from heat and whisk in the softened butter, vanilla extract, and salt until smooth and glossy.
   • Pour the warm custard into a clean bowl and press plastic wrap directly onto the surface to prevent a skin from forming.
   • Let cool to room temperature.

   + Show details− Hide details

   Ready when: Custard coats the back of a spoon and reaches 160°F (71°C) internally; it should be thick and smooth

   Tip: Whisk constantly to avoid scrambling the eggs or creating lumps. If lumps form, strain the custard through a fine-mesh sieve. Cooling it completely before layering prevents the choux from becoming soggy.

5. 5

   Assemble the layers

   • Once the choux base has cooled completely and the custard is at room temperature, spread the cooled strawberry-rhubarb compote evenly over the choux layer.
   • Follow with an even layer of the cooled custard, spreading it gently with an offset spatula to cover the compote completely.
   • Work carefully so the choux doesn't break apart.

   + Show details− Hide details

   Ready when: Both compote and custard are spread evenly with no gaps

   Tip: If the choux cracks when spreading, don't worry—the layers will hold everything together. Work gently to minimize disturbance.

6. 6

   Make and apply the chocolate glaze

   • In a small saucepan, combine the chopped chocolate, butter, and corn syrup.
   • Set over low heat and stir frequently until completely melted and smooth, about 2–3 minutes.
   • If needed, remove from heat and continue stirring until fully combined.
   • Pour the warm glaze over the custard layer and spread it evenly with an offset spatula or the back of a spoon, working quickly before it sets.
   • The glaze should cover the entire surface in a thin, even layer.

   + Show details− Hide details

   Ready when: Chocolate is completely melted and glaze is smooth and pourable

   Tip: Don't overheat the chocolate or it may become grainy. Low heat and frequent stirring ensure a silky glaze. Work quickly when spreading so the glaze doesn't cool and become difficult to smooth.

7. 7

   Chill and set

   • Transfer the assembled bars to the refrigerator and chill for at least 20 minutes, until the chocolate glaze is set and firm to the touch.
   • This also allows the layers to set and makes cutting much cleaner.

   + Show details− Hide details

   Ready when: Glaze is set and no longer tacky to the touch

   Tip: Don't skip this step—a cold bar cuts far more cleanly and holds its shape better. You can chill longer (up to 2 hours) without any issues.

8. 8

   Cut and serve

   • Remove the bars from the refrigerator.
   • Using a long, sharp knife dipped in hot water and wiped dry between cuts, cut the pastry into 12 equal bars (3 rows × 4 columns).
   • The warm knife helps prevent the chocolate from cracking and gives clean edges.
   • Serve chilled or at room temperature.

   + Show details− Hide details

   Ready when: Bars are cut into clean portions with minimal chocolate cracking

   Tip: A warm knife (dip in hot water and wipe dry) prevents the chocolate glaze from shattering. Work confidently—hesitant sawing motions cause more cracking than quick, decisive cuts.