This recipe is very sweet. If you find it too sweet, try substituting apple filling rather than cherry filling).
Preheat oven to 350 degrees. Spray a 9 x 13 x 2 cake pan with Pam. Spread the cherry pie filling evenly in the bottom of the pan. Spread dry cake mix and pecans evenly over the cherry pie filling.
Cut butter into small pats 1/8" thick (butter needs to be cold when cutting). Spread the butter pats evenly over the top of everything else.
Bake at 350 degrees for 45-50 minutes until top is golden brown and filling is bubbly. Let cool at least 30 minutes before serving.