Preheat oven to 350 degrees F. Coat a 12-inch pizza pan with nonstick cooking spray.
Prepare the brownie batter according to package directions. Spread the prepared batter evenly over the bottom of the pan. Bake for 20 to 25 minutes, or until a wooden pick inserted in the center comes out clean; let cool.
In a large bowl, beat the cream cheese, confectioners' sugar, and whipped topping until smooth. With a wet table knife, spread the mixture evenly over the brownie pizza, then spoon the cherry pie filling evenly over that. Cut and serve immediately, or cover and chill until ready to serve.