To make the mousse, in a microwave, heat the chocolate over 50% energy level until melted. Transfer it to the food processor or blender with the avocado, vanilla, salt, maple syrup to taste, and enough almond milk to help it get smooth but to stay thick and creamy.
To make the soil, in a microwave, heat the chocolate over 50% energy level until melted. Transfer to a bowl with the Rice Krispies and toss until well coated. Spread it out onto a silpat on a baking sheet and allow to cool in the fridge. Mix in the cacao nibs.
To make the tomb stone, heat the chocolate over 50% energy level until melted. Transfer to a piping bag and snip a tiny corner out. Draw the word RIP or a name on each cookie and allow to cool for a few minutes to set.
To assemble, divide half of the chocolate soil between four glasses or mason jars. Top with mousse and another layer of the soil. Insert a cookie and enjoy!