Easy S'mores in the Oven

Heat oven to 350°F.

Place 9 graham squares on bottom of 9-inch square pan. Top with 36 marshmallow halves; sprinkle with chocolate. Cover with remaining graham squares.

Arrange 4 marshmallow halves, cut sides down, on top of each graham square.

Bake 9 to 11 min. or until marshmallows are puffed and golden brown. Let stand 5 min. Cut into 18 bars with greased knife. Serve warm.