Preheat oven to 400 degrees F. Peel fresh peaches with a vegetable peeler and slice into medium-size bowl. Add berries, then brown sugar, flour, and ginger; toss to coat. Stir in Grand Marnier. Pour fruit into greased 1-½ quart baking dish. Place in oven for about 10 minutes.
While fruit is heating up, combine dry ingredients of oatmeal scone mix in medium bowl. Add beaten egg, milk, and melted butter, stirring just until moist. Don’t overmix.
Remove fruit from oven and drop scone mix onto fruit mixture, forming about 8 mounds. Sprinkle lightly with cinnamon sugar. Bake for about 15 minutes.