Preheat oven to 350 degrees F (175 degrees C). Grease a 13x9-inch baking dish.
Mix oats, sunflower seeds, coconut, brown sugar, cinnamon, and sea salt together in a large bowl.
Stir yogurt, peanut butter, maple syrup, coconut oil, and vanilla extract together in a separate bowl until smooth; add to oats mixture and stir to coat. Mix protein powder and chocolate into the resulting mixture; spread into prepared baking dish.
Bake in preheated oven until browned, about 15 minutes.
