Heat oven to 180C/160C fan/gas 4. Scatter the nuts over a baking tray and toast in the oven for 10 mins, then set aside (they don’t need to cool). Cut the two pieces of rice paper to fit a 20 x 20cm square tin. Line the tin with one sheet of rice paper, brush the sides of the tin with oil, then dust the tin with icing sugar.
Put the honey into a saucepan, then in another saucepan tip in the sugar, glucose and 100ml of water. Put the egg whites in the very clean bowl of a tabletop mixer with a whisk attachment and whisk on a low speed. Heat and boil the honey until it reaches 121C on a digital cooking thermometer, then straightaway pour the honey over the egg whites and set the speed to medium. While the whites and honey are whisking, bring the sugar and water to the boil and keep boiling until the syrup reaches 145C exactly on a digital cooking thermometer. Pour the hot syrup in a slow, steady stream into the beating egg white mixture. Continue beating for about 10 mins until you have a thick, glossy, firm meringue. It’s hard to over-whisk at this stage but easy to under-whisk, so keep going until the meringue looks like sticky chewing gum.
Use a spatula to stir though the nuts (which should still be warm), the vanilla extract and a small pinch of salt. Scrape the mixture into the lined tin, then smooth over to spread the mixture out evenly (if you have an offset spatula, now is the time to use it). Finally, top with the remaining sheet of rice paper and press down. Leave the nougat to set for at least 2 hrs or overnight.
To turn out and portion, use a spatula to loosen the edges of the nougat away from the tin, then invert the tin on to a clean board and use a sharp serated, hot knife to portion into bars or squares. The nougat will keep, stored in an airtight container, for up to a month.