Preheat the oven to 200 degrees Celsius / 400 degrees Fahrenheit.
Heat the water, butter, sugar and salt together in a saucepan and bring it to boiling point. Break the butter into small chunks so that the water doesn't boil before it has melted into it.
Sieve the flour and add it into the water mixture off the heat, stirring vigourously to form a smooth paste.
Return the saucepan over medium heat and continue to stir the mixture for a few minutes to cook out the flour. It will form a smooth, shiny ball that holds its shape together if you roll it around the saucepan (see video).
Cool the mixture by turning it out into a glass bowl and put in the fridge for a few minutes, or spread it out onto a cool, clean surface.
Whisk the eggs together and add slowly into the choux pastry mixture, stirring continuously so it incorporates and forms a silky, glossy mixture that just drops off a spoon.
Pipe your profiteroles. Put the choux pastry into a piping bag and cut 1cm from the end. Pipe small mounds of the choux pastry onto a lined baking tray, leaving a gap between each one.
Flick a tablespoon of water over the choux buns to help them rise.
Bake the profiteroles in the oven for 20 minutes until they are golden brown. Be governed by colour rather than time, as all ovens vary, they may need more time.
Take the profiteroles out of the oven and carefully make a piping hole in the bottom rising the end of a sharp knife. Put the profiteroles back in the oven to dry out for one or two more minutes with the holes facing upwards.
Make your Christmas profiteroles filling. Cut all of the rind off the Brie cheese and then cut it into small chunks. Place the brie and cream cheese into a bowl with the cream cheese and use an electric whisk to blend them together until smooth. Move it in a piping bag, and put the cranberry sauce into another piping bag.
Pipe the profiterole filling: Pipe a small amount of cranberry sauce into the savory profiteroles first, and then pipe in the whipped brie.