Line 9 x 12 inch shallow-sided baking sheet with parchment paper. A large lasagna pan will also work. Set aside.
In bowl, combine yogurt, maple syrup, turmeric, and black pepper. Whisk together to blend. Pour into lined tray and spread out evenly. Scatter with walnuts, flaxseeds, coconut, and barberries or cranberries.
In small saucepan on stovetop, melt chocolate and coconut oil together, stirring until smooth. Drizzle in strands over yogurt.
Freeze tray until bark is firm, preferably overnight. To serve, break bark into chunks. Return any remaining bark to freezer to prevent melting.