Preheat oven to 210°C (190°C fan). Line baking tray with greaseproof paper.

Make choux pastry Place butter, water, milk, sugar and salt in medium saucepan over medium-high heat. Bring to a simmer. Stir until sugar has dissolved. Stir in flour and cook for 30 secs until dough comes cleanly away from sides of pan.

Remove from heat and beat in eggs using wooden spoon, ensuring the first is incorporated before adding the next.

Spoon mixture into piping bag with 2cm-diameter opening (do not attach nozzle at this stage). Pipe 10 thick lines, about 10cm long and about 4cm apart, on lined baking tray. Bake for 30 mins.

Switch oven off and keep door ajar by placing spoon in seal. Allow pastries to cool for 30 mins in oven. Transfer to rack to cool completely.

Place 2/3 cup of cream, liqueur and vanilla seeds/paste into small saucepan over medium-high heat. Bring to a simmer.

Make filling Place white chocolate into medium mixing bowl and pour over hot cream. Stand for 15 secs, then whisk to combine. Refrigerate until cold.

Using knife, prick small hole in one end of each pastry. This is where you will pipe cream through later.

Pipe cream Using electric beaters, whip remaining thickened cream with white chocolate cream until firm peaks form. Spoon into piping bag fitted with 0.5cm nozzle and carefully pipe cream into éclairs.

Make icing Place dark chocolate, icing sugar and butter in heatproof bowl and place over pan of gently simmering water to melt. Stir to combine. Remove from heat.

Dip top of each pastry into melted chocolate and return to wire rack to set. Enjoy!

Tip These éclairs are best eaten the day you make them as the pastry will be nice and crisp, but they will keep for 3 days in an airtight container in the fridge.
These French choux pastries are naughty but oh-so nice! The crème de cacao adds a little je ne sais quoi.