Line an 8-by-8-inch baking pan with parchment paper.

To make the optional macadamia nut crust, in a food processor, combine the macadamia nuts, dates, vanilla, and salt, and process to the consistency of a coarse meal. Transfer the mixture to the prepared pan and press it into an even layer on the bottom.

To make the optional sweet potato layer, steam or boil the sweet potato until it is very soft, 15 to 20 minutes.

Remove and discard the skin along with any brown spots. Mash the sweet potato by hand or in a food processor while slowly adding the coconut cream, a tablespoon at a time, until you reach a nice, thick consistency— similar to that of mashed potatoes.

Spread the mixture over the nut crust or in the bottom of the prepared pan in an even layer.

To make the pudding, in a medium saucepan, combine the cornstarch, sugarcane juice, coconut milk, and vanilla, and mix well to fully incorporate the cornstarch.

Place the saucepan over a medium-low heat and cook, stirring constantly, for 5 to 10 minutes, until the mixture thickens.

Transfer the mixture to the prepared pan.

Refrigerate for 4 to 6 hours or overnight. Serve chilled.