Soft and chewy brown sugar oatmeal cookie bars filled with Nutella chocolate hazelnut spread and chocolate chips. This easy recipe requires very little hands on time, the crust and topping are made from the same mixture.
Preheat oven to 350°F. Line an 8x8 square pan with foil or parchment and spray with nonstick spray. Set aside.
In a mixing bowl, using a hand mixer or stand mixer fitted with the paddle attachment, beat butter and brown sugar until fully combined. Beat in vanilla and egg, scraping the sides and bottom of the bowl as needed. Add flour, oats, baking, soda, and salt, beating until combined.
Place a little more than half of the cookie dough into the bottom of the prepared pan and place the remaining dough (which will be used for the topping) in the refrigerator. Press the mixture in the pan into an even, flat layer (I moisten my fingertips with water and press it in). Bake for 12 minutes.
Remove from the oven and immediately add the Nutella. Since the crust will be soft, you don't want to spread too vigorously. I recommend dolloping the Nutella all around the top of the dough, then using an offset spatula to lightly spread the Nutella into an even layer. The heat from the crust will melt the Nutella slightly, which will make it easier to spread. Sprinkle the Nutella with chocolate chips. Remove the reserved dough from the refrigerator and press it into flat, irregular shaped pieces and place them all over the top of the chocolate.
Bake for 18-22 minutes, until the top is baked and golden brown. After removing from the oven I like to add a few chocolate chips on top, so feel free to do so, if you'd like. Place the pan on a wire rack to cool. The longer these cool, the more "set" the filling will be. Do not cut them while they are hot, as the chocolate will ooze out. I recommend serving them slightly warm so that the chocolate is mostly firm but still a little melted.
Video
Notes
*FLOUR: Flour should be weighed (ideally) or measured using one of the following methods:
Whisk the flour several times to lighten it, scoop a heaping portion, and level it off with the back of a knife.
Stir the flour with a spoon to lighten it, spoon the flour into your measuring cup and level it off.
Recipe updated May 2023. The crust/topping was made a little softer and chewier.