Pour the cashew milk and coconut cream into a small pan. Heat gently over medium-high heat until nearly boiling, then remove from heat and stir in the chocolate pieces until melted and the mixture is smooth.
In a large bowl, whisk together the egg yolks, vanilla extract, and maple sugar. Whisking constantly, slowly pour hot chocolate into yolks. Strain through a very fine-mesh sieve into a large measuring cup or bowl.
Divide the mixture among 2- to 4-ounce espresso cups or small ramekins. Set filled cups in a large roasting pan that has been positioned on the center rack of the oven. Add hot tap water to the pan, halfway up the sides of the cups. Cover pan with foil; use a fork to prick holes in the foil.
Bake until edges are lightly set (lifting foil to check) but the center is still jiggly — it will set as it cools — 35 to 40 minutes. Transfer cups to a wire rack to cool completely. Refrigerate at least 3 hours before serving.
If desired, pipe (or use a clean paintbrush!) to create a shape on top with melted chocolate.