In a saucepan over medium heat, melt 113g unsalted butter until it foams and browns with a nutty aroma. Remove from heat and cool slightly.

In the same pan, combine browned butter, 120ml water, 120ml milk, 1 tbsp sugar, and 1/4 tsp sea salt. Bring to a boil. Add 125g sifted flour and stir vigorously until a thick dough forms.

Continue cooking the dough for 2–3 minutes until it forms a ball and leaves a film on the pan. Transfer to a mixing bowl and cool for 5 minutes.

Gradually beat in 230g of eggs to the dough, mixing thoroughly after each addition until it forms a smooth batter that drops in a 'V' from a spoon.

Pipe 3cm mounds onto parchment-lined baking sheets. Bake at 375°F (190°C) for 30–35 minutes until puffed and golden. Cool completely.

In a saucepan, heat 200g sugar and 60ml water without stirring until deep amber. Remove from heat immediately.

In a bowl, whisk 4 egg yolks, 1 egg, 45g cornstarch, 0.5 tsp salt, and half of 500ml hot milk. Temper, return to pot with remaining milk and caramel, and cook until thick. Stir in 1 tsp vanilla and 30g butter. Strain and chill.

In a small bowl, combine 1 tsp powdered gelatin with 2 tbsp cold water. Let sit 5 minutes, then microwave 10 seconds to dissolve.

Whip 200ml cold heavy cream to soft peaks. Slowly add melted gelatin and continue whipping to stiff peaks.

Whisk chilled pastry cream until smooth. Fold in stabilized whipped cream to make light, pipeable diplomat cream. Chill 30 minutes.

Use a skewer or small knife to poke a hole in the bottom of each puff. Insert a piping bag with a small round tip and gently squeeze to fill with salted caramel diplomat cream until full.

Using a star tip, pipe a small decorative swirl of cream on top of each filled puff. Dust with 1 tbsp powdered sugar before serving.