Opera Recipe

Prepare and preheat

Preheat oven to 220°C (425°F). Line a 13x18-inch (half sheet) baking tray with parchment, leaving some overhang. Lightly grease the parchment.

Whip egg whites

In a clean, dry bowl, whisk the 4 egg whites until frothy. Gradually add 60 g granulated sugar and continue to whip to soft peaks. Set aside.

Make batter

In a separate bowl, whisk the 3 whole eggs with 45 g granulated sugar and the vanilla until thick and slightly ribbony. Fold the whipped egg whites into the whole-egg mixture gently in two additions.

Combine dry ingredients

Sift together almond flour, sifted all-purpose flour and cocoa powder. Gently fold the dry mixture into the egg mixture until just combined, keeping the batter airy.

Add butter

Fold in the cooled melted butter in a thin stream until incorporated. Scrape batter into the prepared tray and spread into an even layer about 1 cm thick.

Bake and cool

Bake for 5–8 minutes until the sponge springs back and feels set (do not overbake). Remove from oven and allow to cool in the tray for 2–3 minutes, then invert onto a rack or second sheet of parchment. Trim edges to straight sides when cool. You need one full sheet for assembly; if making separate layers, cut as required.

Prepare and preheat

Reduce oven to 180°C (350°F). Line another 13x18-inch sheet with parchment and draw a rectangle template if you plan exact layer sizes (for Opera typically 9x13-inch finished rectangle).

Whip egg whites

Whisk 3 egg whites to soft peaks. Gradually add 60 g granulated sugar and continue to whisk until glossy stiff peaks form.

Fold dry ingredients

Sift together powdered sugar, almond flour, all-purpose flour and add salt. Fold the dry mixture gently into the meringue in two additions, keeping volume.

Pipe or spread and bake

Spread the dacquoise mixture into an even rectangle on the prepared tray to the desired thickness (approx 6–8 mm). Tap to remove large air bubbles. Bake 10–12 minutes until lightly golden and set. Cool completely on the tray.

Bloom espresso

Dissolve 2 tsp instant espresso powder in 15 ml hot water. Set aside to cool slightly.

Make sugar syrup

In a small saucepan, combine 100 g granulated sugar and 30 ml water. Clip a candy thermometer to the pan and heat the sugar to 118°C (244°F) — soft-ball stage.

Whisk yolks

While the syrup heats, whisk the 4 egg yolks in a clean bowl until smooth. When the syrup reaches 118°C, remove from heat and, with the mixer running on low speed, slowly pour the hot syrup into the yolks in a steady stream. Increase speed and whip until the mixture is pale and cooled to room temperature (approx 5–7 minutes).

Add butter and coffee

Reduce mixer to low and add the soft butter, a few tablespoons at a time, whipping until smooth and emulsified. Add the dissolved espresso, vanilla extract and salt. Continue to beat until fully combined and silky. If the buttercream curdles, keep beating; if too warm, chill briefly and rewhip.

Make ganache

Place chopped dark chocolate in a heatproof bowl. Heat the 120 ml heavy cream until just simmering, then pour over the chocolate. Let sit 1–2 minutes, then stir gently from center outward until smooth and glossy. Add cold 20 g butter cubes and 1 tbs corn syrup if using; stir until fully incorporated. Cool slightly until pourable but not runny (around 35–40°C).

Prepare syrup

Combine 120 ml strong brewed espresso and 30 g sugar in a small saucepan. Heat gently, stirring until sugar dissolves. Remove from heat and stir in 15 ml coffee liqueur if using. Cool to room temperature.

Trim and cut layers

Trim the cooled chocolate sponge and the dacquoise to matching rectangles (for example 9x13 inches) or desired size. You will need alternating layers: chocolate sponge, coffee buttercream, almond sponge, buttercream, chocolate sponge (or build as chocolate/almond/chocolate depending on your sheet yields). Typically Opera has 7 thin layers (3 cake layers and 4 buttercream/ganache layers).

Soak cake layers

Using a pastry brush, lightly brush the chocolate sponge layers with the cooled coffee syrup — do not soak to sogginess; just enough to flavor (about 1–2 tbs per layer depending on size).

Layer with buttercream and ganache

Place the first chocolate sponge on a flat board. Spread a thin, even layer (about 4–6 mm) of coffee buttercream over it. Add the almond sponge (dacquoise) on top and press gently. Spread another thin layer of buttercream. Add the next chocolate sponge and spread a thin layer of ganache (or alternate with buttercream). Continue layering until finished, ending with a thin layer of ganache or a final thin buttercream layer covered by ganache for a glossy top.

Chill and level

Chill the assembled cake for 20–30 minutes to firm up for easier trimming. Trim edges to sharp clean lines. If needed, use a hot knife to smooth cut edges.

Glaze top

Pour the slightly cooled ganache over the top of the chilled cake, spreading to the edges and letting it drip slightly down the sides. Use a small offset spatula for a smooth finish. For an extra glossy mirror, strain ganache before pouring and work quickly while ganache is pourable.

Final chill and serve

Refrigerate the assembled Opera for at least 1 hour to set the layers and glaze. Remove from fridge 15–20 minutes before serving to allow buttercream to soften. Cut into thin rectangular slices (classic Opera portions are narrow) with a hot, wiped knife for clean slices.