Whisk together the flour, eggs, milk, melted butter, and salt until smooth. Rest the batter for 15 minutes at room temperature.

Heat the olive oil in a skillet over medium-high heat. Season the chicken with garlic powder, onion powder, black pepper, and 1/2 tsp salt, then cook for 6 to 8 minutes, turning once, until the internal temperature reaches 165°F (74°C). Let it rest for 3 minutes, then chop into small pieces.

Return the skillet to medium heat and add the baby spinach. Stir for about 2 minutes until fully wilted. Set aside with the chicken.

In a medium saucepan over medium heat, melt the butter, whisk in the flour, and cook for 1 minute. Whisk in the milk and heavy cream, then add the garlic powder and remaining 1/2 tsp salt. Cook for 4 to 5 minutes until thick enough to coat a spoon. Remove from heat, stir in the Parmesan, then fold in the chicken and spinach.

Heat a lightly buttered nonstick skillet over medium heat. Pour about 1/4 cup of batter per crepe, swirl to spread, and cook for 1 to 2 minutes until the edges look dry, then flip and cook for 30 more seconds. Stack finished crepes with parchment between them.

Spoon about 3 tbsp of filling onto each crepe, fold and roll closed, and arrange 2 per plate. Spoon extra sauce over the top and scatter the chopped parsley over each serving.