Mixed Berry Cobbler

2 (12 ounce) bags frozen mixed berries
1 (16 ounce) bag frozen boysenberries
1 (18.25 ounce) box white cake mix
1/4 cup granulated sugar
3/4 cup (1 1/2 sticks) butter, melted

Spread the mixed berries on the bottom of an ungreased 13 x 9-inch pan. Sprinkle the white cake mix over the fruit. Spread the boysenberries over the cake mix. Sprinkle the sugar over the boysenberries and slowly pour melted butter over the entire contents. Bake at 350 degrees F for 45 to 60 minutes, until cake mix looks slightly brown. Let cobbler stand until cool enough to serve.

Serve with vanilla ice cream or Cool Whip.