Preheat your oven to 375°F (190°C).
Place the fresh spinach in a pan over medium heat and sauté until completely wilted, then transfer to a clean kitchen towel and squeeze out all excess moisture.
In a medium mixing bowl, whisk together the egg whites, Greek yogurt, crumbled feta cheese, chopped fresh dill, garlic powder, sea salt, and black pepper.
Fold the squeezed spinach into the egg mixture until well combined.
Lightly brush a small oven-safe baking dish or ramekin with half of the olive oil.
Lay one sheet of phyllo dough into the dish, allowing the edges to hang over, brush lightly with the remaining oil, and layer the second sheet on top.
Pour the spinach and egg mixture into the center of the phyllo dough.
Gently fold the overhanging edges of the phyllo dough inward toward the center, leaving the middle slightly exposed.
Bake for 25 to 30 minutes until the filling is set and the phyllo is golden brown and crispy.
Allow the pie to cool for 5 minutes before slicing and serving.