Preheat oven to 400F and line a baking sheet with parchment paper or a nonstick mat.
Add the flour and Greek yogurt to a food processor and blend until you can form a ball of dough. (You can also mix by hand.)
Spray the parchment paper with a bit of cooking spray and roll the dough into a large rectangle (about 11x8).
Mix the cream cheese, cooked chicken, buffalo sauce, and ranch seasoning together in a small bowl.
Cut the dough into 4 equal pieces and add 1/4th of the buffalo chicken mixture to each piece near the center cut line.
Fold the other half of the dough over, sealing the edges all the way around.
Use a fork to crimp the edges to further seal the empanadas and brush the olive oil over each empanada.
Bake for 18-22 minutes or until the tops are golden brown. (Air fry for 14-16 minutes at 375.)