A frosting made without any butter? Yes, it's possible. And yes, it's delicious. This frosting is also WW friendly, and just 1 WW SP (blue) for 1/4 cup (or 1/2 cup for 3 SP).
Strain the Greek Yogurt well through a cheesecloth or paper towels until the consistency is similar to a cream cheese.
Add strained greek yogurt to bowl and mix in powdered sugar and vanilla extract.
If you prefer it sweeter, add powdered sugar a tbsp at a time and a bit more vanilla (1 tsp for 1 cup of yogurt). Correct thin frosting by removing liquid and adding powdered sugar as necessary.
Store in an airtight container in the fridge for up to 4 days.