Photograph: Karen Thomas
Preheat the oven to 160°C, fan 140°C, gas 3. Seperate two of the eggs into egg yolks and whites (reserve the whites for another recipe). Beat 4 eggs and the two egg yolks together in a bowl, then add all the other ingredients for the crème. Beat again, then strain through a sieve into a jug; set aside.
For the caramel, put the sugar and coffee in a heavy-based pan over a medium-high heat and stir to dissolve the sugar. Once dissolved, cook without stirring, swirling the pan occasionally, for 15 minutes. To test if the caramel is ready, drip a little into a ramekin with a spoon. If it hardens quickly, it is ready. If not, cook for a couple more minutes, then retest.
Once the caramel is ready, pour a thin layer into an 18-20cm cake tin or 8 x 175ml ramekins (enough to cover the base) and swirl around very quickly to coat the base before it sets. Allow to set and harden.
Pour the crème into the prepared cake tin. If using ramekins, pour about 3cm of the crème into each one. Place the tin/ramekins in a roasting tin; pour in enough water to come halfway up the sides – this is a bain-marie and allows even baking.
Bake for 20-25 minutes for the individual portions or 40-45 minutes for the large one – they will still have a wobble in the centre that will set on cooling. Remove from the bain-marie, allow to cool, then chill for at least 6 hours or overnight.
Run a thin knife all around the edge of the tin/ramekins. Turn it upside down on to a dish and tap to help it pop out. The caramel should drizzle down the sides, forming a puddle.
Get ahead: make up to 2 days ahead and store in the fridge.
Recipe adapted from My Vietnamese Kitchen by Uyen Luu (Ryland Peters & Small, £16.99)