Place ¼ cup peanut butter in a small, microwave-safe bowl. Heat for 20-30 seconds, or until smooth and pourable.
In a mason jar layer ¼ cup of Greek yogurt. Top with ¼ cup of blackberries, a drizzle of peanut butter, and 2 tablespoons of mixed nuts.
Layer the remaining Greek yogurt, ¼ cup of strawberries, remaining mixed nuts and the remaining peanut butter.
If desired, add a spritz of whipped cream to the top of the yogurt parfait before sprinkling a tablespoon of dried Goji berries over the top. Or simply sprinkle the Goji berries and enjoy!