- 1 cup (2 sticks) unsalted butter, melted
- 2 cups cups granulated sugar
- 4 eggs
- 1 tsp vanilla
- 1/3 cup unsweetened cocoa powder
- 1 1/2 cups all-purpose flour
- 1/2 tsp salt
- 1/2 cup (1 stick) unsalted butter, softened
- 1 cup powdered sugar
- 1/3 cup chocolate-hazelnut spread, such as Nutella
- 1/2 tsp vanilla extract
- Pinch of salt
- 1 Tbsp heavy cream
Preheat oven to 350°. Lightly spray a 9” x 13” baking dish with canola spray.
To make the brownies, in a large bowl, combine butter and sugar. Add eggs and vanilla and stir to combine.
In a medium bowl, sift together cocoa powder, flour, and salt. Add to wet ingredients and stir until flour just disappears. Pour into prepared dish and spread into an even layer. Bake until lighter in color, batter appears set and firm, 20-25 minutes. Let cool completely.
To make the filling, in a stand mixer fitted with the paddle attachment, beat together butter and powdered sugar on low until well blended. Add chocolate-hazelnut spread and increase speed to medium. Beat for 2 minutes. Add vanilla and salt and beat for an additional 30 seconds. Add cream and beat for about 1 minute, until mixture lightens slightly in both color and texture. Transfer to a piping bag or sealable plastic bag.
Using a heart cookie cutter or stencil, cut 12 hearts out of brownies. Transfer to a work surface and turn over 6 hearts to be tops of sandwiches. Pipe filling onto 6 heart “bottoms.” Top with 6 heart tops.