Preheat oven to 350°. Spread butter evenly over 9x13 pan.
Combine berries, sugar, juice, and cornstarch in a medium saucepan. Cook over medium heat, stirring occasionally, until thickened. Pour into 9x13 baking pan.
2 lbs triple berry mix, 1 cup sugar, 1 tablespoon lemon juice, 4 tablespoon cornstarch
Dump the yellow cake mix in a bowl. Look on the back of the box and see how much water it calls for. Now add ¼ cup to that and substitute that amount with milk. For example: if the back of the box calls for 1 cup of water, then you would add 1 ¼ cups milk. Just to be clear, you do not add any water to the batter. Only milk. Whisk until combined. Pour over berry filling and carefully spread batter across pan.
1 box butter yellow cake mix, 1 cup milk, 6 tablespoon butter
Bake for 40-50 minutes. Serve with ice cream.
vanilla ice cream