Ingredients: 1/3 cup (5 Tablespoons; 72g) unsalted butter, softened to room temperature. 1/2 cup (100g) packed light brown sugar. 2 large eggs, at room temperature. 2 teaspoons pure vanilla extract. 1 and 1/4 cups (370g) Nutella, divided. 1/2 teaspoon salt. 3/4 cup (94g) all-purpose flour.