Preheat oven to 400°. While oven is preheating, let pie crust thaw. Pierce the bottom of crust with a fork a few times. Bake pie crust for 6 minutes. Remove from oven and set aside.
While pie crust is pre-baking, prepare the filling on the stove top. Drain cherries and reserve 1 cup of the liquid. In a medium saucepan, combine sugar and cornstarch; slowly stir in reserved cherry liquid until blended. Bring to a boil over medium heat; cook and stir for 2 minutes or until thickened. It doesn't take long.
Remove from heat; stir in cinnamon and food coloring if desired. Gently fold in cherries.
Pour into crust. Cover edges loosely with foil. Bake at 400 degrees for 20 minutes. If the edges are browning too fast, cover them with foil.
While the pie is baking, prepare the topping. In a large bowl, combine topping ingredients and mix well. Remove the foil if you used it. Spoon topping over pie.
Reduce oven to 350 degrees and bake 15-20 minutes more or until topping is lightly browned. Cool on a wire rack 1 hour. Chill 4 hours or overnight before cutting.