Prepare the Chocolate Coating: Set up a double boiler over a gentle simmer, ensuring the water doesn't touch the bowl. Add the chocolate and avocado oil to the bowl, stirring occasionally until completely melted and glossy. Remove from heat to cool slightly.
Whip the Yogurt Base: In a mixing bowl, combine the Greek yogurt, almond butter, maple syrup, cinnamon, and sea salt. Whisk with a spatula until the mixture is smooth, uniformly colored, and airy.
Assemble the Jars: Divide the yogurt base evenly among the three jars, smoothing the top of each to create a level surface.
Pour the Magic Top: Gently pour the slightly cooled chocolate over the yogurt in each jar, tilting to guide the chocolate into a thin, even layer that covers the entire surface.
Garnish and Set: Immediately sprinkle the wet chocolate with toasted slivered almonds and cacao nibs, if using.
Flash Chill: Transfer the jars to the freezer for about 15 minutes, or until the chocolate forms a solid, crackable shell. Serve immediately.