Pat the chicken dry and cut into 1-inch cubes, then season with 1 teaspoon salt, 1 teaspoon pepper, and 1 teaspoon garlic powder.
Heat a deep 12-inch skillet or large pot over medium-high heat and add 2 tablespoons olive oil.
Add the seasoned chicken in a single layer and cook 3–4 minutes without moving, then stir and cook another 3–4 minutes until cooked through and lightly browned.
Stir in the orzo, then pour in 4 cups chicken broth and 1½ cups heavy cream; bring to a simmer.
Simmer, stirring and scraping the bottom occasionally, until the orzo is tender, about 10–12 minutes.
Reduce heat to low and stir in 4 ounces cream cheese, 1/4 cup Parmesan, the minced garlic, drained artichoke hearts, and the remaining 1 teaspoon salt until the cheeses melt and form a creamy sauce.
Add the spinach and cook, stirring regularly, until wilted and fully incorporated into the sauce.
Serve warm, garnished with additional Parmesan and freshly cracked pepper if desired.