Heat oven to 350°F (325°F for dark or nonstick pan). Generously spray bottom and side of 8- or 9-inch round cake pan with baking spray with flour.
In large bowl, beat cake ingredients with electric mixer on low speed until moistened, then on medium speed 2 minutes, scraping bowl occasionally. Pour into pan.
Bake and cool as directed on box for 8- or 9-inch rounds.
Place berries in medium bowl. In 1-quart saucepan, heat preserves and apple juice to boiling, stirring frequently. Pour over berries; toss berries until coated with preserves mixture. Let stand 5 minutes.
Gently cut off any dome from top of cake, using serrated knife, to make top level. On serving plate, place cake, sliced side down. Arrange berries on cake; drizzle with syrup remaining in bowl. Sprinkle with sliced almonds. Store leftover cake covered in refrigerator.