Berry Upside Down Cake

1/2 cup chopped walnuts
1 cup fresh or frozen blueberries
1 cup fresh or frozen raspberries, halved
1 cup sliced fresh strawberries
3/4 cup sugar
1 package (3 ounces) raspberry gelatin
1 1/2 cups miniature marshmallows
1 package (18-1/4 ounces) yellow cake mix
2 eggs
1 1/4 cups water
2 Tbsp. Canola oil

In a greased 13-in. x 9-in. baking dish, layer walnuts and berries; sprinkle with sugar, gelatin and marshmallows. In a large bowl, combine the cake mix, with eggs, water and oil; beat on low speed for 30 seconds. Beat on medium for 2 minutes.

Pour over top of fruit and nuts in pan. Bake at 350° for 30-35 minutes or until a toothpick inserted near the center comes out clean. Cool for 5 minutes before inverting onto a serving platter. Refrigerate leftovers. Yield: 15 servings.