Shake the can of coconut milk vigorously for a few seconds. In a heavy saucepan bring 1 1/4 cups of the coconut milk, sugar, and the salt (just) to a simmer over low heat.
While that is heating, in a seperate bowl whisk together the remaining coconut milk, arrowroot powder, spice blend (or curry powder), and cocoa powder. It should look like a chocolate frosting.
When the coconut milk and sugar mixture has started simmering take about 1/4 cup of it and whisk it little by little into the arrowroot mixture, creating a slurry. Turn down the heat to the very lowest setting. Now drizzle the arrowroot slurry mixture into the simmering pan of coconut milk whisking vigorously all the while. Keep whisking until the pudding comes back up barely to a simmer and thickens up a bit, about a minute.
Remove the saucepan from heat, continue whisking while it is cooling for about a minute. Now whisk in the chocolate and vanilla. Keep stirring until the pudding is smooth. Place in a refrigerator to chill thoroughly. To prevent a skin from forming press plastic up against the surface of the pudding. Serve dusted with the coconut flakes and a tiny pinch of spices (or curry powder).
* For a more pronounced coconut flavor, you might want to add a small splash of coconut extract.