Bumbleberry is a mix of different fruits. Try different fruit combinations, keeping the size similar for even cooking and the total measure of 4 cups. You can also use different cake mix flavors. Easy to suit every taste.
In 9x13 cake pan, melt butter. Sprinkle brown sugar evenly on top. Scatter fruit over sugar.
Prepare cake mix according to package directions. Pour batter evenly over fruit.
Bake 45-50 min or until toothpick inserted in center comes out clean. Let stand 5 min, then turn upside down onto large platter of cookie sheet. Serve warm with generous dollup of whipped cream or ice cream, if desired.