· ½ cup butter· ¼ cup hazelnut liqueur (such as Frangelico®)· ¼ cup chocolate-hazelnut spread (such as Nutella®), or more to taste· 1 cup all-purpose flour, sifted· ½ cup unsweetened cocoa powder· ¼ teaspoon salt· ⅔ cup white sugar· ⅓ cup brown sugar· 2 large eggs eggs· 1 teaspoon vanilla extract· ½ cup semisweet chocolate chips
Step 1Preheat oven to 375 degrees F (190 degrees C). Grease an 8-inch square baking pan or line with parchment paper.Step 2Melt butter, hazelnut liqueur, and chocolate-hazelnut spread together in a small saucepan over medium heat, stirring occasionally, until starting to bubble, about 5 minutes. Remove saucepan from heat and cool slightly.Step 3Whisk flour, cocoa powder, and salt together in a bowl.Step 4Beat white sugar, brown sugar, eggs, and vanilla extract together in a large bowl using an electric mixer until smooth and creamy; slowly mix in butter mixture until smooth. Stir flour mixture into butter-sugar mixture just until batter is combined; fold in chocolate chips, if using. Pour batter into the prepared pan.Step 5Bake in the preheated oven until the top is dry and the edges have started to pull away from the sides of the pan, 20 to 25 minutes. Cool brownies in pan for at least 2 hours before cutting.