Mix oil, brown sugar, egg, milk and vanilla in an electric mixer till well combined.
Add remaining ingredients, except berries and mix well.
Press into greased 9x13 or 10x15 pan. The size pan will determine the thickness of the bars, but either size will work.
Bake 20 minutes at 350° or until a toothpick comes out clean.
Cool and cut into bars.
Wrap in plastic wrap and store in freezer.