Makes about 10 sandwiches.
Start the day before serving.
Set aside about 120ml (1/2 cup) of the coconut milk. Place the rest in a saucepan with the honey and salt. Heat gently, stirring often, until the honey has dissolved.
Gradually whisk the reserved coconut milk into the cornflour then whisk it in to the mixture in the pan.
Stir constantly and heat until it is just simmering and the mixture has thickened enough to coat the back of a spoon, about five minutes.
Whisk in the vanilla extract then transfer to a bowl, cover and chill until completely cold.
Give the cold custard a quick whisk until it is smooth again then churn in an ice cream maker according to the manufacturers instructions.
Meanwhile, line an approx 18x28cm rectangular tin with clingfilm. Spread the churned ice cream out in the tin, cover the top with a sheet of baking parchment and press so that that it is level.
Place the tray in the freezer for at least a couple of hours, until firm.
Place the melted coconut oil in a bowl and whisk in the honey and egg.
Stir in the oats, flour, coconut sugar and cinnamon until well combined then stir in the raisins.
Place the bowl in the fridge, ideally overnight but 30 minutes will do if you don't have time.
Preheat the oven to 180C/350F/gas mark 4. Line two baking sheets with baking parchment.
If you have chilled the dough overnight then it should be firm enough to roll into balls, if you have only chilled it for a little while then you will need to scoop it instead.
Use about a tablespoon of dough per cookie, I weighed mine to get them all the same - 25g per cookie, I got 23 cookies. Roll each portion into a ball and place them well spaced apart on the baking sheets - they will spread. Flatten each ball slightly with your fingers.
Bake for about 10 minutes, until golden and they no longer look 'wet' on top. Leave to cool on the trays for five minutes then transfer to a wire rack to cool completely.
Use an 6cm round cookie cutter to stamp out rounds from the sheet of ice cream; if it is very firm then you may need to let it soften at room temperature for a few minutes. (If your cookies are a different size to mine then you may need a different sized cutter)
Sandwich together two cookies with a round of ice cream and either eat straight away or return them to the freezer until needed.