Preheat oven to 400°F (200°C). Line a large baking sheet with parchment paper or lightly grease it.

In a large bowl, combine the shredded chicken, salsa, cumin, garlic powder, and chili powder. Add the softened cream cheese in chunks and stir until the mixture is smooth, creamy, and well combined.

Lay a large flour tortilla flat. Spoon about 1/2 cup of filling into the center and top with a generous handful of shredded cheese.

Fold in the two sides of the tortilla toward the center, then roll it up tightly from the bottom like a burrito. Place seam-side down on the prepared baking sheet. Repeat with remaining tortillas.

Brush the top and sides of each chimichanga generously with melted butter or spray thoroughly with olive oil.

Bake for 18 to 20 minutes, flipping halfway through if desired, until the tortillas are deep golden brown and crispy.

Let chimichangas rest for 5 minutes before serving. Top with sour cream, guacamole, shredded lettuce, or extra salsa as desired.