Recipe: Black Forest Ice-Cream Cake

I love Black Forest cake - or at least, the whipped-cream-and-sponge confections carried by local bakeries, because authentic Schwarzwälder Kirschtorte is fairly complicated, calls for a liqueur not readily available here, and scorns the notion of calorie control. My brother is fond of it too, so for his birthday I was determined to come up with a version which would be recognisably Black Forest-like without immediately doubling his risk of heart disease. Aquafaba and this ice-cream cake recipe proceeded to save the day.

Black Forest Ice-Cream Cake
Adapted from this recipe at yuppiechef.com

Cake layer

90 g plain flour
50 g caster sugar
2 tbsp unsweetened cocoa powder
1/2 tsp baking powder
1/16 tsp baking soda
45 ml aquafaba (or 1 egg)
2 tbsp milk
3 tbsp canola oil
3 1/2 tbsp water from canned cherries (see below)
1/2 tbsp cherry liqueur or cherry brandy flavouring
180 g Oreo cookies, roughly crushed

Ice-cream layers

411 g can whole tart cherries in water
3 tsp granulated sugar
200 ml thickened cream (35% fat)
45 ml aquafaba or egg whites, chilled
1/8 tsp cream of tartar
190 g sweetened condensed milk
1/2 tsp vanilla essence
1 tsp lemon zest

Prepare the cake 1 day ahead. Grease a freezer-safe springform or silicon tin and line with baking paper. If using a silicon tin, place on a flat baking tray or flan tin to keep it stable. Preheat oven to 180°C.

Whisk together flour, sugar, cocoa powder, baking powder and baking soda. Make a well in the centre and pour in aquafaba, milk, and canola oil. Place cherry water in a microwave-safe bowl or mug and heat 30-60 seconds on high until boiling; add to cake batter. Whisk together until just combined. Stir in cherry liqueur. Mix in crushed Oreo cookies.

Transfer cake batter to the prepared baking tin and smooth out the top. Bake 30-35 minutes until springy to the touch and cooked through. Cool to room temperature, then transfer the baking tin to the freezer. Chill for 45-60 minutes, until frozen solid.

Meanwhile, drain 125 g cherries (reserve the water); halve and set aside in a medium bowl. Transfer the remaining cherries and water to a freezer-proof container and stir in granulated sugar. Place in freezer, stirring every 2 hours to form a slush. 

Using an electric mixer, beat whipping cream to soft peaks, about 5 minutes. Place in refrigerator and clean mixer blades. Beat aquafaba to soft peaks, about 10 minutes. Sprinkle in cream of tartar and continue beating until stiff and glossy, about 5 minutes. Fold aquafaba into cream. Gradually fold in condensed milk, then vanilla essence and lemon zest. Transfer half of the cream mixture to the reserved 125 g cherries and refrigerate the rest. Carefully stir cherries and cream. 

Retrieve frozen cake base from freezer. Quickly spread the cherry cream on top. Freeze for 2 hours until set. Spread remaining cream mixture on top and freeze for 6 hours to overnight, until completely set.

To serve, remove the cake from the pan and peel away the baking paper. Set it on top of a chilled plate and allow to thaw slightly at room temperature, about 10-15 minutes, until it can be cut with a knife. Serve with cherry slush piled on top or on the side.

Notes:

I used two flavours of Oreo cookies (original and chocolate) in equal parts. The cookies can be crushed using a Ziploc bag and a rolling pin, but I find it easier to quickly pulse them in a food processor.

I used homemade aquafaba from boiled soybeans (a little sweet) and chickpeas. They didn't quite whisk past the soft peak stage and collapsed quickly, but the ice-cream came out fine, if a little dense. If you want aquafaba which reliably whisks to stiff peaks, use the water from canned chickpeas.

Canned cherries may look rather pale and unappealing, so you can stir in a few drops of red food colouring to improve their appearance. Fresh cherries can also be used; reserve any juice released while halving and pitting the cherries, and when making the slush, add enough just water to cover the cherries.