In a large bowl, whisk together flour and salt. In another bowl, whisk eggs and milk. Gradually add the wet ingredients to the dry ingredients, whisking until smooth. Stir in melted butter.

Heat a lightly oiled crepe pan or non-stick skillet over medium heat. Pour about 1/4 cup of batter into the pan and swirl to coat evenly. Cook for about 1-2 minutes per side, until golden brown. Repeat with the remaining batter.

In a medium bowl, combine cooked chicken, spinach, cream cheese, Parmesan cheese, garlic powder, salt, and pepper. Mix well until everything is evenly distributed.

Spoon about 2-3 tablespoons of the filling onto one half of each crepe. Fold the crepe in half, then in half again to form a triangle.

Place the filled crepes in a baking dish. You can optionally top with more sauce or cheese if desired.

Bake in a preheated oven at 350°F (175°C) for 10-15 minutes, or until heated through and cheese is melted.