Peach Cobbler Dump Cake

1 (18.25 ounce) box yellow cake mix
1 (32 ounce) can peaches in heavy syrup
1/2 cup butter
Ground cinnamon

Preheat oven to 375 degrees F.

Empty peaches into the bottom of a 13 x 9- inch pan. Cover with the dry cake mix and press down firmly. Cut butter or margarine into small pieces and place on top of cake mix. Sprinkle top with cinnamon.