Mix the cake mix, brown sugar and oats together. Add the oil and the egg and mix well. Pat half of the dough into a prepared 13 x 9-inch pan. Spoon the strawberry topping over the dough, and top with the blueberries. Crumble the rest of the dough over the topping and blueberries.

Bake at 350 degrees for 30 to 35 minutes. Cool and cut into bars.