Heat oven to 350°F (325°F for dark or nonstick pan). Grease 13x9-inch pan. Place cake mix in large bowl. With pastry blender or fork, cut in butter until crumbly. Add almonds; mix well. Reserve 1 cup mixture for topping. Press remaining mixture in bottom of pan. Stir preserves until smooth; carefully spread over base.
In same bowl, beat cream cheese, sugar, flour, salt and egg with electric mixer at medium speed until well blended. Add margarita mix; beat at low speed until blended. Carefully pour filling over base. Sprinkle reserved base mixture over filling.
Bake 34 to 41 minutes or until edges begin to brown and center is set. Cool completely, about 1 hour. Cut into bars. Store covered in refrigerator.