Add 2/3 cup of the canned coconut milk to a saucepan and bring to a simmer. Fill a glass with 1/3 cup water, add the cornstarch and turmeric, then whisk until there are no lumps.
Pour the cornstarch slurry into the saucepan and whisk while it thickens. Add the sugar and vanilla, then simmer for 30-60 seconds. Remove from the heat, set aside, and cover with plastic wrap.
Unroll the thawed puff pastry and cut it into six squares with a sharp knife. Bring the four corners towards the center of the pastry, pressing firmly to seal. Brush each pastry with soy milk.
Then add around 1 tbsp of the custard to the center of each pastry (don’t overfill them!). Optionally, add around 2 tsp of jam and sprinkle each with a little coconut sugar/brown sugar.
Remove the custard Danishes from the oven and allow cooling. Add a few berries to each pastry and optionally drizzle with nut/seed butter – then enjoy!