How to Make It
In a medium bowl, whisk the cornstarch and salt. Slowly whisk in 1 cup of the milk until smooth. In a medium saucepan, combine the remaining 2 cups of milk with the coconut milk and 2 cups of the sugar and bring to a simmer, whisking until the sugar dissolves. Gradually whisk in the cornstarch mixture and cook over moderate heat, whisking constantly, until very thick, about 6 minutes. Off the heat, whisk the custard for 1 minute. Let cool for 10 minutes. Spoon the custard into twelve 3/4-cup ramekins. Refrigerate until chilled and firm, at least 6 hours or overnight.
In a blender, puree the raspberries with the liqueur, lemon juice and the remaining 2 teaspoons of sugar. Strain the puree through a fine sieve. Serve the coconut pudding with the raspberry sauce on top.