01 - Line a baking sheet with parchment paper and set aside.
02 - In a medium mixing bowl, combine the peanut butter, Greek yogurt, maple syrup (or honey), and vanilla extract. Stir until the mixture is completely smooth and uniform.
03 - Using a small cookie scoop or heaping teaspoon, portion the mixture onto the prepared baking sheet, spacing each mound slightly apart. Aim for approximately 24 bites.
04 - Transfer the baking sheet to the freezer and freeze for at least 2 hours, or until the bites are completely firm to the touch.
05 - Place the chopped dark chocolate and coconut oil (if using) in a microwave-safe bowl. Heat in 30-second intervals, stirring between each interval, until the chocolate is fully melted and smooth. Alternatively, melt using a double boiler over gently simmering water.
06 - Remove the frozen bites from the freezer. Using a fork or dipping tool, submerge each bite into the melted chocolate, allowing any excess to drip off before returning it to the parchment-lined baking sheet.
07 - While the chocolate is still wet, immediately sprinkle the top of each bite with flaky sea salt. Work quickly before the chocolate sets.
08 - Return the coated bites to the freezer for 10 to 15 minutes, or until the chocolate shell is firm and fully set.
09 - Transfer the finished bites to an airtight container and store in the freezer for up to 1 month. Serve directly from the freezer or allow to thaw slightly for a creamier texture.