Chocolate Raspberry Trifle

OK this here is a whopper of a dessert - almost a full gallon of deliciousness! That being said, it's not too hard to put together. The individual components are quickly made, and, best of all, you can - and really should! - make it ahead of time!
Serves 16
To use frozen raspberries, thaw them first and include the juice. Assemble the trifle (except for the top cream layer) at least 6 hours or up to two days before serving. Use a glass bowl (preferably with straight sides) with at least a 3 1/2-quart capacity. 
Custard:
  • 2 teaspoons vanilla extract
  • 1/2 teaspoon instant espresso powder
  • 1/3 cup (3 1/2 ounces) sugar
  • 3 tablespoons cornstarch
  • 2 tablespoons Dutch-processed cocoa powder
  • 1/4 teaspoon table salt
  • 3 cups whole milk, divided
  • 3 large egg yolks (reserve the whites for the cake)
  • 4 ounces bittersweet chocolate, chopped fine
  • 5 tablespoons unsalted butter, cut into 5 pieces
Raspberry Filling
  • 1 pound (3 1/4 cups) raspberries, divided
  • 3 tablespoons sugar
  • 1 teaspoon cornstarch
  • pinch of salt
Cake
  • 1 1/3 cup (5 1/3 ounces) cake flour
  • 3/4 cup (5 1/4 ounces) sugar
  • 1 1/2 teaspoons baking powder
  • 1/4 teaspoon table salt
  • 1/3 cup vegetable oil
  • 1/4 cup water
  • 2 large eggs, separated, plus three large egg whites (reserved from custard)
  • 2 teaspoons vanilla extract
  • 1/4 tsp cream of tartar
Whipped Cream
  • 2 cups heavy cream, divided
  • 4 teaspoons sugar, divided
6 tablespoons rum (optional)
For the custard:
  1. Combine vanilla and espresso powder in a small bowl; set aside.
  2. Whisk together sugar, cornstarch, cocoa powder and salt together in a large (3 quart) saucepan. 
  3. Whisk in 1/2 cup of milk and the egg yolks until fully incorporated, making sure to scrape the corners of the saucepan well.
  4. Whisk in remaining 2 1/2 cups of milk until incorporated.
  5. Set saucepan over medium heat and whisk gently until mixture is thickened and bubbling over entire surface, 5 to 8 minutes. Cook for 30 seconds longer, then remove from heat.
  6. Immediately add chopped chocolate and butter and whisk until incorporated and smooth. Whisk in vanilla mixture.
  7. Pour custard through a fine mesh strainer into a shallow bowl. Press lightly greased parchment paper or plastic wrap against the surface of the custard and refrigerate until cool, at least 4 hours or up to 2 days. 
For the Raspberry Filling:
  1. ​Place half the raspberries, sugar, cornstarch and salt in a small (1 qt) saucepan. Using potato masher, thoroughly mash berries in saucepan.
  2. Set over medium heat and cook, stirring frequently, until the sugar dissolves and the mixture thickens and is bubbling, 3 to 5 minutes.
  3. Pour over remaining raspberries in a bowl and stir to combine. Set aside to cool.
For the Cake:
  1. Adjust oven rack to middle position and heat to 350°. Lightly grease a half-sheet pan (18" x 13"), line with parchment paper, then grease the parchment paper.
  2. Whisk the flour, sugar, baking powder and salt together in a large bowl. Whisk in oil, water, egg yolks and vanilla until a smooth mixture forms.
  3. In a stand mixer fitted with the whisk attachment, whip the 5 egg whites and the cream of tartar on medium speed until foamy, about 1 minute. Increase speed to high and whip until soft peaks form, 2 to 3 minutes.
  4. Transfer 1/3 of the egg whites to the batter and whisk in gently until the mixture is lightened. Using rubber spatula, gently fold in remaining egg whites.
  5. Pour batter into prepared sheet and use an offset spatula to gently spread the batter evenly throughout the pan. Bake until cake springs back when pressed lightly in center, 10 to 13 minutes.
  6. Transfer cake to wire rack and let cool for 5 minutes. Run a knife around the perimeter to loosen the cake then invert onto a cooling rack. Remove parchment and then re-invert onto a second cooling rack. Let cool completely, at least 30 minutes.
For the whipped cream:
  1. Whip 1 cup cream with 2 teaspoons sugar together until soft peaks form. 
To assemble:
  1. Trim 1/4" off each side of cake: discard (or eat!) trimmings. Cut cake into 24 equal squares, each roughly 2 1/2" square. 
  2. Briefly whisk custard until smooth.
  3. Spoon 1/2 cup of the raspberry compote into the bottom of the trifle bowl and spread over the bottom.
  4. Tear 1 cake square into 4 pieces and pile in center of bowl. Shingle 10 cake squares, fallen domino-style, around the bottom of the trifle, placing edges again the bowl wall. Tear another cake square into pieces and fill in the center. (Optional: drizzle 3 tablespoons of rum over the cake pieces.) Spoon half of the custard over the cake and spread evenly.
  5. Spoon the whipped cream evenly over the custard.
  6. Gently spoon the rest of the raspberry mixture over the cream and spread evenly. (Tip: start with small dollops along the edge of the bowl to make sure you get clean layers.)
  7. Repeat layering with remaining 12 cake squares, pressing firmly but gently on the cake to remove any gaps in layers. (Optional: sprinkle with remaining 3 tablespoons rum.) Spread remaining custard over the cake.
  8. Cover trifle with plastic wrap and refrigerate at least 6 hours and up to 2 days.
  9. Before serving, whip the remaining 1 cup cream and 2 teaspoons sugar to soft peaks. Spread cream over the top of trifle. Decorate if desired, and serve.
From Cook's Illustrated No. 179 - November & December 2022.

Notes:
  • So, my family of 10 ravenous adults only managed to get through half of this, with seconds! Next time I may halve this.
  • If you lack a trifle bowl, you can assemble this in a 4 qqart clear glass/pyrex bowl - it won't look nearly as pretty but who care's, it's delicious!
  • You can also use cups/glasses and assemble individual trifles.