Heat oven to 350°F (325°F for dark or nonstick pans). Spray bottoms and sides of two 8- or 9-inch round cake pans with baking spray with flour.
Make and bake cake mix as directed on box for 8- or 9-inch rounds. Cool 10 minutes. Run knife around side of pans to loosen cakes; remove from pans to cooling rack. Cool completely, about 1 hour.
In medium bowl, beat cream cheese and butter with electric mixer on medium speed until fluffy. Beat in powdered sugar and vanilla.
On serving plate, place 1 cake, rounded side down. Spread with 1 cup frosting. Sprinkle 1 cup of the raspberries over frosting. Top with second cake, rounded side up.
Frost side and top of cake with remaining frosting. Arrange remaining 1 cup raspberries on top of cake along edge.
In 1-quart saucepan, heat jelly over medium heat, stirring constantly, until melted. Brush melted jelly over berries. Garnish with mint leaves. Store covered in refrigerator.