Method

• 1.
  Preheat the oven to 180°C. Place 150ml of water, butter and icing sugar in a saucepan and bring to a simmer. Take off the heat, add the flour and beat the dough for 1–2 minutes or until it easily comes away from the sides of the pan. Cool for 5 minutes.
• 2.
  Add the egg, a little at a time, beating well before you add more. Depending on the size of your eggs, you may not need to use all the egg to reach a dropping consistency. Just keep adding and beating until you have a glossy paste that you can dollop with a spoon or pipe through a bag.
• 3.
  Line an oven tray with baking paper and dollop 2 teaspoons of the mixture for each puff, allowing room for rising. Bake for 10 minutes, then increase the oven temperature to 190°C and bake for a further 8 minutes or until the dough has puffed up and turned golden. Turn the oven off.
• 4.
  Keep them in the oven, with the door open, for 10 minutes. Remove and cool at room temperature.
• 5.
  For the mascarpone filling, combine all ingredients, except for the cream, well. Fold in the whipped cream to combine. Cut puffs in half and fill with the mascarpone mixture, dust with icing sugar and extra zest, to serve.