In a bowl, whisk together the milk, butter, vanilla and salt. Add the cake mix and whisk until no lumps remain. Add the chocolate chips and pour into a microwave-safe mug. Microwave on high until puffed up and firm, about 2 minutes 10 seconds. Let cool for 5 minutes.
Top the cake with coconut whipped cream and toasted coconut.
Open the can of coconut milk, scoop out the solid coconut cream on top and put in a stand mixer with the sugar. Beat on high until stiff peaks form, 5 to 10 minutes.