*Note: it’s very important to chill the can first ahead of time, ideally overnight, so that the white cream layer separates from the water in the can. You only want to scoop out that firm white layer of cream, and leave all the water behind for other uses (or discard). I also recommend using Thai Kitchen full fat coconut milk here -- I've had the best results with it for these types of recipes.
**The reason for gently warming up the mixture at this stage is that sometimes if it's too cold it can bake differently as a result, creating a sort of milky / creamy filling that's different to the texture and look of a butter tart.