For the profiteroles with white chocolate filling, first mix the water and butter and bring to the boil. Remove from the heat, add the flour, return to the heat and stir until the ball of dough separates from the bottom of the pan. Let cool.
Line a baking sheet with baking paper. Preheat the oven to 210 °C.
Mix the eggs into the mixture one at a time to make a smooth batter. Place small portions of the dough on the baking sheet with enough space between them (either with spoons or a piping bag), sprinkle a little water on top. Place in the oven for about 10-15 minutes. Turn off the oven. Make a small hole at the bottom of the profiterols and put them in the turned down oven for 5 minutes.
In the meantime, prepare the filling. Coarsely chop the white chocolate. To do this, mix the pudding powder, cinnamon and a little milk and a little sugar. Bring the milk and remaining sugar to a boil and stir in the pudding mixture. Let it thicken a bit and then stir in the chocolate and possibly the rum. When the chocolate is completely melted, cover the filling and let cool.
Stir again before using. Pour into a piping bag and pipe into the hole of the profiteroles. Serve the profiteroles with white chocolate filling.