Bake the cake, chill overnight, then cut into 1” cubes.
Prepare the custard: Whisk together coconut sugar, arrowroot, cocoa powder, and salt in a medium saucepan. Add almond milk and whisk to combine. Heat on medium, whisking frequently, until it begins to boil. Boil 2-3 minutes, whisking constantly until thickened. Remove from heat, transfer to a glass bowl, place a piece of plastic wrap on top touching the top surface of the custard. Refrigerate overnight (or at least 8 hours).
Prepare the coconut whipped cream: Scoop out the solid part from the can of coconut cream. Whip with a hand beater until smooth and fluffy. Add sweetener and vanilla, whip until combined. If it gets too thin while mixing, refrigerate 30 minutes to re-thicken.
Assemble the trifles: layer chunks of cake, chocolate custard, berries, whipped cream. Repeat until the dish(es) are filled to the top.
Enjoy!