Thursday, October 14, 2010

October 2, 2010: Vanilla slice

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.


  1. I really want a piece now!

  2. Hmm. Back in the day, I would have whisked the cornflour/custard powder into a bit of milk, then added it to the sugar / rest of milk.

    It looks delicious! I love how you can see the teensy little vanilla seeds!

  3. I enjoyed it very much and want more!

  4. WOW! nice job!!

  5. WOW! Looks amazing. I love vanilla slice.

  6. This looks like a great recipe. thanks for sharing :)

  7. I whisk the custard powder briskly in the milk first - cold - to get it dispersed and then, once completely dispersed, stir with a wooden spoon as it heats through, being sure to scrape the bottom of the pot as it tends to gel down there.

    BTW, I'm not vegan but check your custard powder for milk solids (and the puff pastry for butter, of course).

  8. K and Toby - happy to share it with you, after all I wouldn't have made it without your cravings!

    Carla & Lisa - it's not too difficult either, highly recommended. :-)

    Thanks, Cherrie Pie. :-)

    Penny and Kitchen Hand, thanks for sharing your thoughts. I did whisk the custard powder into the milk at room temperature and didn't have any lumps at that stage; it was more uneven thickening later when I did put it over heat. It definitely starts on the bottom of the pot, I didn't dare stop stirring and scraping for a second!

    Kitchen Hand, I was surprised last year to find that the first custard powder I picked off the supermarket shelf was vegan! Just cornflour and sugar with colouring and flavouring additives (... which has me wondering whether I need to buy custard powder at all). Borg's is my puff pastry of choice.

  9. Zuckerbaby here (I can't remember my login details to comment!)

    Nice work - that's a gorgeous looking slice!

    My favoured way of avoiding terrifying lumps is to use a double boiler to cook the custard powder. In a metal or pyrex bowl, whisk 1/3 of the soymilk into the custard powder until smooth & then add the rest of the milk, place over a saucepan of boiling water & whisk continually until thickened. It's labour intensive but has provided the most consistently lump-free custard that I've made.

  10. I made custard to fill cannoli last week and I whisked it until it started to thicken then immediately took it off heat and continued stirring and then put it back on a very low heat and continued to whisk until it was the desired thickness. It always seems to thicken more when it cools too.
    Hope thats a bit of help :)


  11. Cindy, vanilla slice is one of my staple desserts I do when in need of something quick for any gatherings. I can knock one out in under an hour now.

    Definitely agree about using pre-made puff, so much easier. And yep, the shrinking puff got me at the start too, but not I know to cut it a bit bigger. And canned passionfruit is fine for me too.

    As for lumpy custard powder, again, I've done the straining thing too first two times I made it. Trick to not having lumps is to slowly pour the milk (or soy) into the dry powder slowly and stir until the custard powder is fully dissolved before putting everything onto the heat. Else, globs of powder stick together and get heated to make custard pearls, which can never be dispersed.

  12. Zuckerbaby, Rose and Thanh - thanks for your custard advice! Much appreciated. :-)