Preheat the oven to 350°F.

Lightly spray a 9x13 baking dish with non-stick spray.

Remove the cherries from the jar, reserving the liquid. Remove stems from 15 cherries and chop the cherries in half.

In a large bowl, mix the dry cake mix with Cherry Dr. Pepper until just combined.

Fold in the chopped cherries gently.

Pour batter into prepared baking dish and bake for 28 minutes, until a toothpick inserted comes out clean.

In a mixer, beat softened butter with reserved cherry juice until creamy.

Gradually add powdered sugar to the butter mixture, beating until smooth and spreadable.

Spread frosting evenly over cooled cake.

Garnish with chocolate shavings and place reserved cherries on top.