Mix chicken, shredded cheese, cream cheese, salt, and garlic powder in a bowl until combined.

Heat a skillet over medium. Lightly butter one side of a tortilla.

Place tortilla butter-side-down, spread 1/8 of the filling on half, fold over.

Cook 2–3 minutes per side until golden and cheese melts. Repeat.

Cut each quesadilla into 3 triangles. Serve warm with salsa or ranch.