Cassel’s flan cassis is one of the most delicious custard tarts I’ve ever tasted and well worth making. Fast and easy to whip up, the trickiest thing may be finding the blackcurrants with their beautiful sharpness to balance the soft sweetness of the custard filling. Top patissier Frédéric Cassel’s creations are just perfect and baking the puff shell together with the filling gives you an amazing flaky pastry. Just thinking of this Parisian custard tart makes me swoon. Making this dream flan became a reality thanks to the blackcurrants Mum gave me from her allotment to bring home. After that there was a slight panic – couldn’t find them anywhere here in Barcelona and foresaw a bleak blackcurrantless future before coming up with the idea of picking out blackcurrants from a frozen pack of Fruits of the Forest from Aldi. Hurray! Please get hold of some too and join me in savouring Frederic Cassel’s flan cassis aka blackcurrant Parisian custard tart! 🙂
The prototypes and options
Prototype 1 was created by adding blackcurrants to the Mori Yoshida flan (recipe here) – very yummy. Then after years looking for Cassel’s flan cassis online I was overjoyed to see his new book on sale with the recipe and made prototype 2 – delicious but with glazing issues. For the final prototype 3 I decided the glaze made of sugar, gelatine and a little blackcurrant purée could simply be replaced with a thin layer of blackcurrant jam. Here are the three prototypes starting from left to right (1-3).
The original recipe’s in Les Fruits Rouges de Mon Jardin by Frédéric Cassel. I adapted a little, reducing the quantities to make a smaller flan, adding a little vanilla bean, chilling the pastry case a while and substituting the blackcurrant glaze with jam (the recipe for the original glaze is included below as an option). Mine is made with homemade inverted spelt puff pastry but you can also use good-quality all-butter puff. You can make this dessert gluten free by using gluten free puff pastry.
Cake ring (or pie mould) – 12cm/4.7in diametre and 4.5cm/1.7in high or a similar size (here’s a cylinder volume calculator link).
- 140 – 180g puff pastry (homemade inverted spelt puff pastry or shop-bought all-butter)
- Grease the inside of the cake ring with butter and place on a baking tray lined with baking paper. Or use a greased pie mould.
- Roll out the pastry to 2-4mm thick.
- Line the cake ring or pie mould. Lightly pinch the pastry on the sides between your thumb (on the inside of the cake ring) and index finger (on the outside) to make the sides even and thin.
- Cut away the extra pastry leaving a little hanging over the edges. Use the remaining pastry for little sweet or savoury rolls, like sausage rolls. Arrange these around the tart to bake at the same time.
- Chill in the fridge 1 – 2 hours.
- 195g/ml full-fat milk
- 65g/ml whipping cream (35%)
- 1/3 vanilla pod – pod plus seeds scraped out and included (optional)
- 65g/1/4 cup + 1 and 3/4 tsp (divided into 2 halves) caster/superfine sugar – I used unrefined golden caster sugar
- 62g beaten egg (1 medium-sized egg plus 1 tsp, reserve the rest for brushing)
- 21g/2 tbsp + 3 tsp custard powder (can be replaced with cornflour/cornstarch/Maizena but the taste and colour will be different)
- 59g/2oz/1/3 cup or more fresh blackcurrants (can be frozen, defrosted)
- Bring the milk, cream, half the sugar and optional vanilla to the boil on low-medium heat in a medium-small heavy-based saucepan.
- In a bowl, whisk to combine the egg and other half of sugar. Whisk in the custard powder to combine.
- Whisk 1/3 of the hot milk into the egg mixture then pour back into the saucepan.
- Whisk constantly for a few minutes until the mixture thickens.
- Pass through a sieve into a clean bowl and allow to cool 10 minutes.
- Sprinkle the blackcurrants over the base of the chilled pastry case
- Spoon in the custard filling and smoothe with the back of a teaspoon (or small offset spatula) then leave 30 minutes at room temperature.
- Brush lightly with beaten egg.
- Preheat oven to 160ºC/320ºF (fan) or 180ºC/350ºF (static).
- Bake 35-45 minutes (at around 30 mins trim the edges around the top of the ring/tin). The tart is done when the pastry is golden brown and the custard is set but jiggling a little when you shake the baking tray to and fro.
- Cool on the tray then on a wire rack an hour or so.
You can leave your flan naked and it looks lovely too…
But if you’d like a glaze there are two options:
Jam glaze: stir a few spoons of blackcurrant jam or warm slightly to make it more spreadable. Brush the top of the flan delicately with the jam or spread with the back of a teaspoon then add extra fresh blackcurrants.
Blackcurrant neutral glaze (as in the book): 5g/1 tsp blackcurrant purée, 40g neutral glaze and some violet hydrosoluble colouring. Mix together (don’t whisk) and brush the warm glaze on the cooled flan. Except when it’s warm it’s pretty liquid so I wasn’t sure about the recipe but it turns out more or less okay.
Eating and storing
The first day at room temperature you’ll have a delightfully creamy flan …
… then after a night in the fridge you’ll have lovely firmer slices you can pick up with your hands.
It isn’t a dessert you’d freeze but store in an airtight container in the fridge and thoroughly enjoy eating within 3 days.
Frédéric Cassel and Fontainebleau
The point of going to Fontainebleau was to look for the famous magical climbing boulders in the forest there. So mum and I tore ourselves away from the cakes in Paris and took a brief train ride out to this peaceful little town. We came across Frédéric Cassel’s pâtisserie and I’m afraid ended up spending quite a lot of time there. Oops. We might even have gone back a little sheepishly three times in one day before returning to Paris with a box of Cassel’s goodies … but don’t tell anyone.
We had a cake picnic with the flan cassis and other treats…
The next year we went back of course and took slices to cycle around the forest, as you do… 🙂
You can see we’re very attached to Cassel’s flan cassis. So it’s been great to be able to make it at home. The glaze doesn’t come out exactly the same but the flavour’s all there.
Later research revealed Cassel was elected pâtissier of the year in 1999 and 2007, headed the French winning team of the 2013 World Pastry Cup and has been President of the prestigious Association Relais Desserts since 2003. Which explains why his cakes and breads are so amazing and why we naturally went a bit overboard eating them. Lol.
Perhaps you’d like a slice of blackcurrant custard tart aka flan parisien cassis? Please help yourself…
Farewell for now dear reader! Wishing you a sweet week and weekend ahead with some happy baking and eating! 🙂 Lili x