Preheat your oven to 425°F (220°C). Place a baking rack in a cookie sheet, or line a large baking sheet with parchment paper or lightly grease it with cooking spray.
Wash and peel the sweet potatoes. Cut them into thin, even-sized fries, about 1/4 inch thick.
In a large bowl, toss the sweet potato fries with olive oil, paprika, garlic powder, salt, and black pepper until evenly coated.
Spread the seasoned fries in a single layer on the prepared baking sheet. Make sure they are not overcrowded to ensure even baking and crispiness.Bake in the preheated oven for 20-25 minutes until they are golden brown and crispy on the edges. If baking them without a rack, flip the fries over halfway through baking. Slice the avocado, halve the grape tomatoes, and crumble the feta cheese. Chop green onions if using them for garnish.
In a small bowl, mix together the Greek yogurt, BBQ sauce, and mayo until well combined. Adjust the seasoning to taste.
Once the fries are done baking, remove them from the oven and transfer them to a serving platter.Top the fries with avocado slices, grape tomatoes, and crumbled feta cheese. Sprinkle with chopped green onions if desired.Drizzle the Greek yogurt BBQ sauce over the loaded fries. Serve immediately for best results.