In a large bowl, add the Greek yogurt, peanut butter, maple syrup, vanilla extract, and a pinch of salt. Mix well to combine.
Add the grapes and gently fold them in until they’re all covered with the yogurt mixture.
Place the grape mixture onto the parchment paper in clusters with about 3 grapes each. You should have about 8-9 clusters.
Put the baking sheet in the freezer to harden for at least 1 hour.
In a small microwave-safe bowl, add the chocolate chips and coconut oil. Microwave on high for 2 minutes, stirring halfway through. Stir until the chocolate chips are melted and smooth.
Place each cluster in the bowl of melted chocolate, using a spoon to fully cover each one with chocolate. Note that you’ll have to work quickly so that the yogurt doesn’t soften. If it starts to soften too much, place the baking sheet back in the freezer to harden before continuing to dip the clusters in the chocolate.
Place the chocolate dipped clusters on the parchment-lined baking sheet and freeze for another 20 minutes.
Optional: drizzle with peanut butter and add flaky salt before serving.