Lightly spray the inside of the CrockPot.
Empty the box of cake mix into bottom of CrockPot...this works best in an oval CrockPot that is at least 4 quart size.
Pour the 1 1/2 cups Sprite soda over the cake mix; then stir well to make a batter.
Add as many cherries as you like to the top of the batter...do not stir into the batter.
Add lid to CrockPot and cook on HIGH setting for 1 1/2 hours. Check cake for doneness. If cake is not done in the center, replace lid and cook another 10 minutes, checking again.
In a small mixing bowl, combine the powdered sugar with the cherry juice and 1 T. Sprite soda....adding more cherry juice as needed to reach desired glaze consistency.
Pour glaze over cake pieces at time of serving and top each serving with diced cherries, if desired.