1.To make crème pâtissière; combine milk, sugar and extract in a small saucepan; bring to the boil. Meanwhile, combine cornflour and egg yolks in a medium heatproof bowl; gradually whisk in hot milk mixture. Return mixture to pan; stir over heat until custard boils and thickens. Cover surface of custard with plastic wrap; refrigerate 4 hours.
2.Preheat oven to 220°C (200°C fan-forced). Grease oven trays.
3.To make choux pastry, combine the water, butter and sugar in a small saucepan; bring to the boil. Add the flour, beat with a wooden spoon over heat until mixture comes away from the base of the pan. Transfer pastry to a medium bowl; beat in eggs, one at a time, until pastry becomes glossy.
4.Drop rounded teaspoons of pastry, about 5cm (2 inches) apart, onto trays.
5.Bake puffs 10 minutes. Reduce the oven to 180°C (160°C fan-forced). Bake about 15 minutes or until golden brown. Cut a small opening in the base of each puff; bake a further 10 minutes or until puffs are dry. Cool on trays.
6.Spoon crème pâtissière into a piping bag fitted with a 3mm (⅛-inch) plain tube; pipe crème pâtissière into puffs through the openings.
7.To make toffee; stir sugar and the water in a medium saucepan over heat, without boiling, until sugar dissolves. Bring to the boil; boil, uncovered, without stirring, until a small amount of toffee dropped into cold water sets hard and can be snapped with fingers.
8.Push one paddle pop stick into each puff. Working quickly, dip puffs in toffee; place on a baking paper-lined oven tray. Stand at room temperature until set. Serve in foil cases.
Serve puff pops within 6 hours of making. When dipping the puff pops in toffee, tilt the pan of toffee to one side, so it’s deep enough to completely coat the pops. Dip one end of each stick in toffee too, this will ensure the pops don’t fall off the sticks.