Combine butter, sugar, flour and eggs in a large bowl and mix with electric mixer on high speed for about 2 minutes.
Stir in milk.
Spray shallow pie dish or baking tray with canola oil. Pour in batter and top with chocolate buttons and fruit, the fruit will sink into the batter when cooking but it is a good idea to punch in the chocolate buttons.
Place in oven and bake for 45 minutes, keep an eye on the batter, when ready the pie should spring back slightly when touched. Serve warm with cold double cream.