Preheat oven to 425°F.
Prepare the dough: Mix flour, baking powder, salt in a bowl. Add Greek yogurt until smooth.
Turn out onto a lightly floured surface and knead for 3-5 minutes until smooth and elastic
Cover dough with a damp towel and let rest 10 minutes.
Roll out each portion on parchment paper to 1/4-inch thickness. Transfer parchment with dough to baking sheets.
Dock dough with a fork to prevent bubbling.
Pre-bake 5–7 minutes until slightly firm.
Remove from oven and spread buffalo sauce evenly, leaving a 1/2-inch border.
Add chicken evenly over sauce.
Sprinkle mozzarella and a few feta crumbles on top.
Bake 10–12 minutes until cheese is melted and bubbly.
Remove from oven, top with green onions and drizzle lightly with Greek yogurt ranch.
Let cool 2–3 minutes, slice and serve.