Preheat oven to 325 degrees Fahrenheit.
Combine the frozen cherries, diced apple, brown sugar, orange zest, orange juice, and 1 teaspoon of the cinnamon in a medium bowl.
Lightly mix together in a big mixing bowl and set aside.
In the bowl of an electric mixer (I use a KitchenAid) fitted with the paddle attachment, beat the eggs on medium-high speed for 2 minutes.
After 2 minutes, switch the mixer to a medium speed and add 1 cup of the granulated sugar, butter, vanilla, and sour cream and beat just until combined.
After 1 minutes, turn your mixer to low speed and slowly add the flour and salt.
Pour the fruit mixture evenly into a 10-inch glass pie plate.
Pour the batter over the fruit, covering it completely.
Combine the remaining 1 tablespoon of granulated sugar and ⅛ teaspoon of cinnamon and sprinkle it over the batter. Bake for 1 hour.
Serve warm or at room temperature. Top with vanilla ice cream.