Grease and line an 8-inch pie tin. Then, melt the dairy-free butter for the base and add this and the crushed biscuits to a bowl. Stir well to combine.
Spoon the biscuit mixture into the tin and press down with the back of a spoon. Set in the fridge to chill.
Meanwhile, put the Vege-Gel and cold water into a jug and mix well before setting aside.
Add the caster sugar, golden syrup and 60ml of the water to a pan and stir over a low heat until melted. Then bring to the boil and cook for 5 minutes or until golden.
Remove from the heat and stir in the butter and cream. Then add the caramel flavouring and Vege-Gel mixture and mix again until well combined.
Return this mixture to the heat and carefully bring to the boil, stirring continuously.
Working quickly, pour the hot caramel mixture onto the base and chill until set (around 2 hours).
Once set, spread a layer of butterscotch sauce over the top and decorate with spun sugar.