Gooey chocolate hazelnut brownies (Printer-Friendly Version)

# What You'll Need:

→ Filling

01 - 1 (13 oz) jar Nutella

→ Brownie Batter

02 - 4 tablespoons unsalted butter
03 - 8 ounces semi-sweet chocolate (such as Ghirardelli 60% bittersweet chocolate baking bars)
04 - ½ cup vegetable oil
05 - 1½ cups powdered sugar, sifted
06 - 2 eggs plus 1 egg yolk
07 - 1 teaspoon vanilla extract
08 - ¾ cup all-purpose flour
09 - 1 tablespoon cornstarch
10 - ½ teaspoon salt
11 - ½ cup chocolate chips

# Let's Cook!:

01 - Line an 8x8 inch square baking pan with parchment paper, leaving extra paper hanging over the sides as handles. Spread the entire jar of Nutella in a thin, even layer over the parchment paper in the pan. Place the pan in the freezer for at least 1 hour, or until the Nutella is completely frozen solid.
02 - Once the Nutella is frozen, carefully remove the frozen Nutella sheet (with parchment) from the pan and return it to the freezer. This allows the pan to come back to room temperature while you prepare the brownie batter. Preheat your oven to 325°F (165°C).
03 - In a small saucepan over low heat, melt the butter. Add the semi-sweet chocolate to the melted butter and stir until completely melted. Remove from heat and whisk in the vegetable oil and vanilla extract. Allow this mixture to cool slightly.
04 - In a large bowl, sift the powdered sugar. Add the eggs and egg yolk and mix with a hand mixer or whisk until just combined. Be careful not to overmix. Stir the cooled chocolate mixture into the egg mixture.
05 - In a separate bowl, whisk together the flour, cornstarch, and salt. Gently fold this dry mixture into the chocolate batter using a spatula, being careful not to overmix. Stir in the chocolate chips.
06 - Line your 8x8 pan with fresh parchment paper. Pour half of the brownie batter into the pan and spread it evenly. Take the frozen Nutella sheet from the freezer, remove the parchment paper, and place the Nutella layer on top of the brownie batter. Pour the remaining brownie batter over the Nutella and gently spread to cover completely.
07 - Bake in the preheated oven for 35 minutes, or until the edges are pulling away from the sides and the center is set. Note that you can't test for doneness with a toothpick due to the Nutella center. Allow brownies to cool in the pan for 30 minutes, then use the parchment paper handles to lift them out onto a wire cooling rack. Let cool completely for at least 1 additional hour before cutting.

# Recipe Notes:

01 - These brownies cut best when completely cooled
02 - The frozen Nutella layer is key to achieving a distinct gooey center
03 - Store in an airtight container at room temperature for up to 3 days
04 - For an extra indulgent dessert, serve warm with vanilla ice cream