Preheat the oven to 320f and line a 20cmx20cm baking tin with baking parchment. Melt one third of the white chocolate. You can do this in the microwave in 30-second bursts (stirring each time) or in a bowl over some simmering water. Put to one side.
Spoon out the mixture into the prepared baking tin. Push the mixture to the corners and smooth it with the back of a spoon. Top with cherries from the cherry pie filling, pushing them into the mixture slightly.