Preheat oven to 350°F and generously grease a 9-inch pie dish or cake pan with butter.
In a large bowl, mix together flour, sugar, and fruit cocktail (with the juices) until just combined.
Transfer batter to the prepared pan.
Slice remaining butter into small pats and place on top of batter.
Bake cake for 35-40 minutes or until top is golden in color.
Allow cake to cool for a minimum of 10 minutes before serving.
