Preheat oven to 350°F with oven rack in bottom third position. Line bottom of an 8-inch square baking pan with aluminum foil, allowing foil to extend about 2 inches over two opposite sides of pan.

Meanwhile, in a microwave-safe bowl, heat the chocolate chips in the microwave at 50% power until melted and smooth, 1 to 2 minutes, stirring every 15 seconds. Stir in the chocolate-hazelnut spread.

Buttery, Sweet & Salty Dessert Bars. This toffee bar recipe has everything you need in a dessert bar, a buttery shortbread ...

Sprinkle the remaining 1/2 cup of toffee pieces, 1/4 cup of M&Ms, and 1/4 cup of chocolate chips over the top of the batter. Bake until a wooden pick inserted in the center comes out clean, 40 to ...