Preheat the oven to 325 degrees.
Lightly grease a 9-inch cake pan, or 10-inch pie plate.( A 10-inch is better, or see note below*)
In a medium bowl, mix the cranberries, apples, brown sugar, orange juice and zest, and cinnamon and toss to coat. Set aside and make the cake.
In another bowl, beat the eggs until lighter and fluffier--about 2 minutes. Add the sugar, butter, vanilla, and sour cream and mix well.
On low speed, add the flour and salt slowly and mix just until no pockets of flour remain.
Pour the fruit into the bottom of your baking dish.
Spread the batter over the fruit as evenly as possible. It will be thick.
Bake until the fruit is bubbly and hot and the cake is set--45 to 50 minutes or so. Check it with a toothpick--if it comes out clean it's done. Great warm or at room temperature.