Walnut, whiskey and salted caramel pie

Ingredients

• 200 g walnuts
• 4 eggs
• 1 1/2 tbsp plain flour
• 30 ml rye whiskey
• Scraped seeds of 1 vanilla bean
• Pure icing sugar and thickened cream or ice cream, to serve
• Sweet pastry
• 1 2/3 cups plain flour
• 60 g pure icing sugar, sieved
• 1 tsp salt
• 120 g butter, chilled, coarsely chopped
• 3 egg yolks
• Salted caramel
• 200 g caster sugar
• 100 ml cream
• 80 g butter, coarsely chopped
• 1 1/2 tsp salt