To make vanilla cream, in a medium heavy-based saucepan, bring the milk, vanilla and 1/4 tsp salt to a simmer over medium heat. In a medium bowl, whisk the egg yolks, sugar and cornflour. Gradually whisk warm milk mixture into egg yolk mixture. Return milk mixture to the saucepan. Whisk constantly over medium heat for 2 mins or until cream is very thick and smooth. Remove from heat and whisk in the chilled butter. Transfer to a shallow container. Cover with plastic wrap, pressing directly onto the surface. Chill for 1 hour or until the cream is cold and set.
Meanwhile, position racks in centre and top third of the oven and preheat to 200°C (180°C fan-forced). Line 2 large baking trays with baking paper. Draw four 9cm circles on each sheet of baking paper, spacing each circle at least 5cm apart. Turn over the baking paper.
In a medium saucepan, bring milk, butter, sugar, ⅔ cup (160ml) water and 1 tsp salt to the boil over medium-high heat. Add the flour and stir constantly for 2 mins or until the mixture forms a ball of pastry dough and the taste of the flour has cooked out of the dough.
Transfer dough to the bowl of a stand mixer and beat on medium speed for 4 mins or until the dough cools to room temperature. Add the eggs, 1 at a time, beating well after each addition. Transfer half the dough to a large piping bag fitted with a 1.5cm closed star nozzle. Using the baking paper as a guide, pipe 4 circles, applying even pressure and stopping piping just before you close off the circle. Repeat with remaining dough to make 8 circles.
Whisk the egg white with 1 tsp water in a small bowl. Lightly brush each circle with egg wash and sprinkle with the almonds. Bake for 15 mins. Reduce the oven temperature to 170°C (150°C fan-forced) and bake for a further 20 mins or until the puffs are a deep golden brown. Using a paring knife, poke small holes in both sides of each puff. Transfer to a wire rack to cool.
In a large bowl, toss the peaches, nectarines, apricots and plums until well combined.
In the clean bowl of a stand mixer fitted with a whisk, beat the softened butter on medium speed for 1 min. Add half the vanilla cream and beat until combined. Add the remaining vanilla cream and beat for 3 mins or until light and airy. Transfer the vanilla cream mixture to a clean piping bag fitted with a 1.5cm closed star piping nozzle.
Using a serrated knife, halve each puff horizontally. Spoon 1½ tbs of the raspberry jam over the base of each puff. Top with the stone fruit mixture. Pipe vanilla cream mixture over the stone fruit mixture and top with the top of each puff. Dust with the icing sugar and serve immediately.