Preheat oven to 350 degrees F. Lightly spray a 9 by 9-inch baking pan with butter flavored cooking spray; set aside.
In a blender, puree prunes and applesauce. Transfer to a medium mixing bowl. Add the brownie mix, egg whites, oil, and raspberry liqueur or water to mixing bowl. Beat for 1 minute with a wooden spoon until smooth. Transfer to prepared baking pan; set aside.
In a small saucepan over medium-high heat, melt the preserves. Drizzle over brownies. Swirl with a table knife.
Bake in preheated oven for 30 to 35 minutes. Remove and cool completely before cutting.
For the raspberry sauce:
Puree thawed raspberries, honey, and liqueur in blender. Push through a fine mesh strainer; set aside.
To serve, spoon 1 to 2 tablespoons coulis on a plate. Place brownie in center of coulis. Garnish with 3 to 5 fresh raspberries and a fresh mint sprig.