Preheat oven to 350 degrees F. Line an 8-x-8-inch baking pan with aluminum foil. Spray with nonstick spray. Set aside.
In the bowl of your stand mixer, cream together butter and sugar, about 1-2 minutes. Add salt, eggs, and vanilla and continue stirring until fully incorporated. Add flour and baking powder and mix until just combined. Reserve ½ cup of dough. Press remaining dough into the prepared baking pan. Top with cherry pie filling. Drop remaining batter (1/2 cup) in small pieces over the cherry filling.
Place in the oven and bake for 50-60 minutes or until golden brown. Remove from the oven and place pan on a wire rack to cool completely. Once cooled prepare the glaze. Whisk together confectioners’ sugar and milk until smooth and drizzle over the bars. Cut into 12 squares and serve.