Preheat the oven to 375°F (190°C). Line a 9×9 inch baking pan with parchment paper, leaving a little overhang for easy removal.
Make the dough base: In a large bowl, mix the melted butter and brown sugar until combined. Add flour, baking powder, and salt. Mix until a soft, crumbly dough forms.
Press and layer: Press about ⅔ of the dough into the bottom of the prepared baking pan to form an even base.
Add cherry filling: Pour the cherry pie filling evenly over the dough layer.
Top with crumble: Use your hands to crumble the remaining dough over the top of the cherry layer. It doesn’t have to be perfect—rustic is beautiful.
Bake: Bake for 40–50 minutes, or until the top is golden and the filling is bubbling around the edges.
Cool: Let cool in the pan for at least 1 hour (this helps it set). Lift out using the parchment paper and slice into 16 bars.
Serve: Enjoy as-is, à la mode, or with a cherry pie latte for breakfast.