In a mixing bowl, combine Greek yogurt, smooth peanut butter, protein powder. Stir well until all the ingredients are thoroughly combined.
Line a baking sheet or tray with parchment paper. Using a spoon or ice cream scoop, place circular dollops of the yogurt mixture onto the parchment paper.
Leave enough space between each dollop to insert a popsicle stick. Insert a popsicle stick into each dollop. Sprinkle the peanuts overtop of each frozen yogurt bar.
Place the baking sheet in the freezer and let the yogurt dollops freeze completely, for about 2-3 hours.
Right before removing the frozen yogurt bars from the freezer, prepare the dark chocolate coating. Fill a small saucepan halfway with water and bring it to a simmer over low heat. Place a heatproof bowl on top of the saucepan, making sure the bottom of the bowl doesn't touch the water. Add the chopped dark chocolate and the coconut oil to the bowl and stir continuously until melted and smooth.
Remove the frozen yogurt dollops from the freezer. Working quickly, dip each dollop into the melted dark chocolate, allowing any excess chocolate to drip off. Place the dipped bars back onto the parchment paper. Optionally, sprinkle the frozen yogurt bars with flaky sea salt.
Once all the bars are dipped, return the baking sheet to the freezer and let the bars freeze completely, for another 1-2 hours or until firm.
Once fully frozen, transfer the ice cream bars to an airtight container or individual plastic bags. Store them in the freezer until ready to serve. Enjoy! :)