White Chocolate Wattleseed Cake with Passionfruit Curd
This delightful recipe was inspired by the bloom of sunshine yellow wattle flowers dotting the Australian landscape, heralding the start of spring. Native Australian wattleseed imparts a delicately warm, nutty aroma that compliments the white chocolate cake layers, while the roasted macadamias provide a subtle crunch. A layer of tangy passionfruit curd not only brightens and balances out the sweetness, but poetically mirrors the vibrant wattle hue.
Makes a four layer 15cm (6”) cake
Serves 8-12 people
Baking Notes
Wattleseed is a native Australian ingredient that can be sourced from most local specialty food stores or purchased online. It is typically sold as a roasted, ground spice and has a delicate flavour with nutty, coffee-like undertones.
Ingredients
White Chocolate Wattleseed Cake
185ml (3/4 cup) whole milk
1 tsp wattleseed (roasted and ground)
45g macadamia nuts
200g unsalted butter, coarsely chopped
100g good-quality white chocolate 300g caster sugar
125g brown sugar
1 tsp vanilla paste
¼ tsp fine sea salt
250g plain flour
1 ½ tsp baking powder
3 large eggs, at room temperature
Wattleseed Swiss Meringue Buttercream
2 tbsp whole milk
¾ tsp wattleseed (roasted and ground)
3 large egg whites
135g caster sugar
200g unsalted butter, softened
1/8 tsp fine sea salt
Passionfruit Curd
3 large egg yolks
90g caster sugar
45g unsalted butter, coarsely chopped
Pulp of 3-4 passionfruit (60ml)
Zest of 1 large lemon (2-3 tsp)
Juice of 1 large lemon (80-100ml)
1/8 tsp fine sea salt
Method
White Chocolate Wattleseed Cake
1) Preheat oven to 165°C (145°C fan-forced) and grease or line two 15cm (6”) cake pans with greaseproof paper.
2) Place milk and wattleseed in a small saucepan, and gently warm on low-medium heat until steaming. Remove from heat and allow to steep while preparing the rest of the batter.
3) Place macadamia nuts on a tray and roast in oven until golden and fragrant (4-6 minutes). Allow to cool, then finely chop and set aside for cake assembly.
4) Melt butter, white chocolate, sugars, vanilla and salt in a medium saucepan over low heat. Once the butter and chocolate have melted, add wattleseed-infused milk and stir until smooth. Transfer mixture to large bowl and allow to cool for about 10 minutes.
5) In a medium bowl, sift plain flour together with baking powder, then slowly add to melted ingredients, whisking gently until combined. Take care not to overmix. Gently whisk in eggs until smooth.
6) Divide batter evenly between cake pans, weighing pans to ensure equal volume.
7) Bake in the lower third of preheated oven for approximately 50-55 minutes, or until cake tester comes out clean. Cover the cake at 40 minutes if browning significantly.
8) Allow cakes to cool in pans for 10 minutes, then transfer to a wire rack and allow to cool completely
Wattleseed Swiss Meringue Buttercream
1) Place milk and wattleseed in a small saucepan, and gently warm on low-medium heat until steaming. Remove from heat and allow to steep while preparing the buttercream.
2) Place egg whites and caster sugar in heatproof bowl over small saucepan of simmering water, ensuring the base of the bowl does not touch the water.
3) Allow the sugar to dissolve, whisking intermittently, heating to 65°C to ensure egg whites are pasteurized.
4) Allow mixture to cool to room temperature, then whisk in free-standing mixer until white, glossy, soft meringue peaks form.
5) Very slowly add small 1cm cubes of softened butter until buttercream is light and fluffy. Slowly add wattleseed-infused milk and salt while continuing to whisk ensuring buttercream is still light and fluffy
Passionfruit Curd
1) Lightly whisk egg yolks and sugar together in large clean bowl until pale and thick but not frothy.
2) Melt butter, passionfruit, lemon juice, zest and salt together in a medium saucepan over low heat.
3) Add egg yolk and sugar mixture to saucepan and stir constantly over low-medium heat until in turns a deep yellow colour, and thickens enough to coat the back of a spoon (approximately 5- 10 minutes).
4) Remove from heat and allow to cool completely. If not using immediately, pour cooled curd into sterilised jar and keep in fridge.
5) Note there will be approximately one third to one half of the passionfruit curd remaining after drizzling the cake. You can either serve the remaining curd as a condiment with the cake, or reserve the excess to enjoy with another dessert.
Assembly
1) Assembling this cake is easiest when the cake is slightly chilled, and the buttercream and curd are at room temperature.
2) Level each cake by slicing off the cake domes, then cut them in half lengthways to yield four cake layers in total. Use the base of one layer for the base of the cake, and the base of the other layer (turned upside down) for the top of the cake to avoid crumbs in the buttercream.
3) Place the first layer on a round cake plate or turn-table and spread a layer of frosting on the top, smoothing with a palate knife. Sprinkle with finely-chopped roasted macadamia nuts.
4) Repeat frosting and sprinkling macadamia nuts for the second and third cake layers (the top of the cake doesn’t require any macadamia nuts).
5) Place the final cake layer on top and cover the top and sides of the cake in a thin layer of frosting, allowing portions of cake to show through, giving a ‘naked’ appearance. Allow to chill for a couple of hours or overnight.
6) To serve, gently spoon passionfruit curd over the cake, allowing a little to drip down the sides.
7) Note there will be approximately one third to one half of the passionfruit curd remaining after drizzling the cake. You can either serve the remaining curd as a condiment with the cake, or reserve the excess to enjoy with another dessert.
Enjoy!
Salma Sabdia is the creative powerhouse behind fabulous baking blog, The Polka Dotter. Click here to check out her blog, here to follow her on Instagram and here on Facebook.
