Preheat oven to 350 degrees F. Line a baking sheet with parchment paper and set aside.
Prepare brownie batter as instructed on the box, adding water, eggs, and oil. Pour batter into prepared baking sheet, spreading it in a thin, even layer. Bake for 18-20 minutes.
Remove from oven and allow to cool 30-45 minutes.
While brownie is cooling, make raspberry coulis. In a medium saucepan set over medium heat, combine 6 ounces of raspberries, sugar, and 1/4 cup water. Stir well and bring to a boil. Reduce heat to medium-low and simmer.
Combine 1 teaspoon water and cornstarch in a small bowl, whisking until combined, then stir in into the saucepan with vanilla. Simmer for 3-4 minutes until thickened. Remove from heat and cool to room temperature.
Use a small heart-shaped cookie cutter to cut 12 hearts from the brownie sheet. Place one layer on a plate, pipe fudge icing around the edge, then spoon 2 tablespoons of raspberry coulis inside. Stack another layer of brownie on top, pressing down the edges lightly. Pipe a small heart in the middle of the layer, then arrange fresh raspberries around the outer edge, nudging them up against the icing so they don't move. Add more icing to the inner heart until it's as tall as the berries, then place a third brownie layer on top. Like the first layer, pipe fudge around the edge, then spoon in 2 tablespoons of raspberry coulis. Layer the final heart on top, pressing down the edges lightly.
Dust with powdered sugar, and garnish with shaved chocolate and more fresh raspberries.
Amount Per Serving
Calories1063kcalCalories from fat 310
% Daily Value
Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs: