If using pre-made crust, place crust on pizza pan. If using a crust mix, prepare according to directions. After crust is mixed, spread crust dough into a 13 x 9-inch baking pan, making sure to leave a small ledge around pan. Bake crust as per directions, cooking until crust is almost done.
Melt butter with the garlic powder. Make sure mixture is evenly mixed. When crust is almost done, spread garlic butter mixture evenly on crust. Bake 5 minutes.
Place cooked and cubed chicken on crust and top with cheese. Bake for 25 minutes at 350 degrees F or until cheese is melted and golden brown.
Serve immediately. Salsa can be added on top of pizza when it is finished.