1. Make the Pastry Shells:

• Pulse flour, salt, and butter in a food processor until crumbly.
• Add sugar and orange zest, pulse briefly.
• Add egg mixture and pulse until dough forms.
• Roll out and line four 8x3cm tartlet tins. Chill for 30 mins.
• Bake at 190°C (170°C fan) for 10–15 mins with baking beans, then remove beans and bake 5–10 mins more. Cool completely.

2. Prepare the Custard:

• Heat cream with vanilla seeds and pod until bubbling at edges. Let infuse for 5 mins, then discard pod.
• Beat eggs and sugar in a bowl, then slowly mix in warm cream.
• Strain mixture and pour into tart shells.
• Bake at 150°C (130°C fan) for 18–22 mins until just set but still wobbly. Chill for 30 mins.

3. Make the Caramel:

• Grease a metal tray with oil.
• Heat sugar and water in a pan without stirring until deep golden.
• Pour onto tray and cool completely.
• Break into shards and blitz into fine crystals.

4. Finish the Tartlets:

• Sprinkle caramel crystals over each tart.
• Grill gently or use a kitchen torch to melt and caramelize the sugar.
• Chill again briefly before serving.