There are many, many reasons I love J. Kenji López-Alt, but introducing me to aquafaba is probably near the top of the list.
Aquafaba is the slightly pungent, somewhat turbid water left over from boiling chickpeas (or theoretically, other legumes, but chickpeas apparently work best). Recently, it was discovered that aquafaba can function as a vegan egg white substitute.
I'm not remotely vegan, alas, but I have been watching my calories, and eggs are as calorie-ridden as they come. Also, raw eggs somewhat disgust me. I think it's a combination of the slimy texture, the bits of reddish material you can sometimes see in them, the off-putting smell, and those annoying shards of shell which get into the bowl and then refuse to come out. Not that I'd turn down an omelette, or a hard-boiled egg, or even a poached egg on a baguette slice - anyway, the prospect of replacing egg whites with a non-eggy substitute is very appealing. Also appealing: painlessly dealing with those annoying recipes which call for, say, 8 egg whites but only 2 egg yolks. WHY??!!
Yeah, I'm kinda irreverent when it comes to cookery.
So I found this recipe from an old Family Circle book and substituted in aquafaba. It worked really well. Nobody suspected a thing.
Also, I cut out a bunch of sugar and added weight measurements and stuff.
Pineapple Streusel Cake
Adapted from a recipe in Fabulous Fast Cakes, Murdoch Books, 1994
125 g unsalted butter
150 g caster sugar
90 ml aquafaba (or 2 eggs)
450 g can pineapple chunks or crushed pineapple
50 g desiccated coconut
80 g brown sugar
Preheat oven to 180°C. Grease and line a deep 20 cm cake pan.
If using pineapple chunks, crush roughly using a blender, wet grinder or food chopper. Strain the crushed pineapple, reserving 125 ml of the pineapple juice.
Melt butter and caster sugar over low heat, or in a microwave on medium-low, stirring until
homogeneous. Separately, combine aquafaba and pineapple juice.
Sift flour into a large mixing bowl and make a well in the centre. Pour in the butter and aquafaba mixtures into the well, and stir using a wooden spoon until just combined. Transfer half of the cake batter into the prepared pan and smooth the top using a spatula.
Mix crushed pineapple, desiccated coconut and brown sugar until evenly combined. Spread on top of the cake batter in the pan. Carefully add the remaining cake batter and smooth the top. Bake for 1 hour, until the top is crisp and a knife inserted in the centre of the cake comes out clean. Allow the cake to rest for 10 minutes before turning out of the pan. Serve warm.
Notes
To prepare aquafaba, cover about a cupful of chickpeas with water and allow to soak for about 4-8 hours, until the peas have swelled up. Transfer to a saucepan, topping up the water to just cover the chickpeas, and bring to the boil. Simmer for 45 minutes, until the chickpeas are soft. Remove chickpeas with a slotted spoon and continue simmering the water on low heat, until reduced to half the initial volume. The aquafaba will be more viscous than water, but less viscous than egg white.
Alternatively, just use the water from canned chickpeas directly.
The base of the cake may be very moist, so be careful when turning it out of the pan.
