Instructions

• Preheat the oven to 350 degrees F.
• Spray a 13×18×1-inch baking sheet with nonstick cooking spray.
• In a large bowl, whisk the sour cream, the buttermilk, the vanilla, the egg whites, and the vegetable oil together.
• Sift the cake mix into the sour cream mixture and stir until just combined.
• Pour the batter into the prepared baking sheet.
• Bake the cake until a toothpick or fork inserted in the center comes out clean, about 12-15 minutes.
• Allow the cake to cool completely.
• While the cake is baking, in a small saucepan whisk the Danish dessert into the cold water.
• Place the Danish dessert mixture over medium heat and bring it to a boil, whisking constantly.
• Boil until thickened, about 1 minute. Transfer it away from the heat immediately.
• Stir the raspberries into the sauce.
• Set the sauce aside to cool. You can place the saucepan on a hot pad in the fridges to quicken the cooling time. If you do so, be sure not to leave it in the fridge for too long. You don't want it to set up in the pan.
• While the sauce and cake cool, in a medium bowl cream the cream cheese and the butter together with a hand mixer until smooth and there are no lumps.
• Beat the powdered sugar into the cream cheese mixture until combined.
• Fold the imitation whipped cream into the cream cheese mixture.
• Dollop the whipped frosting evenly onto the cooled cake and then spread it into an even layer.
• Spread the cooled sauce over the cream cheese frosting layer.
• Refrigerate the cake for at least 2 hours and up to 4 hours.
• Slice and serve chilled.