In a medium saucepan, whisk together the cornflour and 50ml of the plant milk. Once smooth, add the remaining plant milk, vanilla extract and caster sugar.
2 ½ tablespoon cornflour, 450 ml plant milk, 3 teaspoon vanilla extract, 50 g caster sugar
Place over medium low heat and stir constantly until the custard thickens.
Remove the pan from the heat then immediately add the vegan butter. Stir vigorously until fully melted and incorporated into the custard.
50 g vegan butter
If serving warm, serve immediately. Alternatively, cover the surface of the custard with plastic wrap and leave to cool to room temperature then store in the fridge.