When we breakfasted at Naked Espresso a few weeks ago, their menu taunted us with the existence yet unavailability of vegan vanilla slice. The chronically sweet-toothed K was particularly disappointed, so when we cooked together a fortnight later we made sure our own home-grown vanilla slice was on the menu. There are a few different version floating around the internet and I picked the one appearing on the International Vegetarian Union web page. It uses frozen puff pastry sheets, a filling based on soy milk and custard powder, and is topped with passionfruit icing. (Yep, it was the passionfruit that had me hooked.)
Frozen puff pastry is obviously a time-saver, and a cheat that I'd happily use again. The one hitch is that it tends to shrink as it bakes, so the frozen rectangle that I cut to fit neatly in my baking tray ended up undersized. I can think of no obvious solution to this problem and was more than happy to spoon up the pastry-less custard edges as they were.
I was a little wary of the custard, as I'm wary of any dessert involving this much soy, but the flavour was just fine. We used a carton of the finest re-released Bonsoy and the scrapings of a bourbon-soaked vanilla bean to create a sweet, smooth custard that set up nicely in the fridge overnight. The 'smooth' bit was in doubt as I cooked; I don't have much experience using custard powder and was alarmed to see it setting in little chunks in the heated saucepan rather than thickening gradually. Fearing jellied gobs in the finished product, I pushed it all through a sieve, making quite a mess in the process, and I'm not sure whether it's necessary. (Any custard powder experts out there? Help a sister out.)
The crowning glory of this slice was the passionfruit icing. I tripled the amount of passionfruit that the recipe called for and have no regrets - these rich creamy squares desperately need that sour, fruity edge. (This reminded me of the brilliantly unorthodox berry coulis slash across the vanilla slices at Sorrento's Continental Hotel.) Fresh passionfruit is available right now but I imagine that the canned stuff would do OK if the vanilla slice angels were whispering to you out of season.
This is definitely the kind of 'I-can't-believe-it's-vegan!' dessert that I'll be making again. While it doesn't resemble the crisp-pastried cream-custard versions that gourmets flock to, it'll trounce your best memories of suburban bakery snot blocks.
Vegan vanilla slice
(based on a recipe at the International Vegetarian Union website)
2 sheets frozen puff pastry, thawed
1 cup castor sugar
3/4 cup cornflour
1/2 cup custard powder
1L soy milk
60g vegan margarine
2 teaspoons vanilla essence
2 cups icing sugar
1 teaspoon vegan margarine
pulp from 3 passionfruits
1 teaspoon water
Heat an oven to 200°C. Bake the puff pastry sheets on lightly greased trays for about 6 minutes, until lightly browned. Set them aside to cool.
In a saucepan, stir together the sugar, cornflour and custard powder. Whisk in the milk and add the margarine. Set the custard over medium heat to melt the margarine and bring the mixture to boil. Remove the custard from the heat and stir in the vanilla. At this point I strained it; if your custard looks lumpy you might want to, too.
Set a layer of pastry into a baking dish, trimming and reshaping it as needed. Pour over the custard and spread it out so that it's roughly even. Place the second pastry sheet on top, again trimming and reshaping as needed. Refrigerate the slice.
To make the icing, stir together all the ingredients until smooth. Retrieve the slice from the fridge and spread over the icing as smoothly as you care to. Return the slice to the fridge for several hours (preferably overnight) until the custard has set firm. Slice and serve.