When the bars have cooled completely, carefully pull the ends of the parchment paper to remove the bars from the pan. Cut the ends off each side Using a sharp knife, creating a smooth finish. Measure 2.5 inches across the left side and bottom of the large square. Gently use a knife to make a light crease across and over, creating a grid on the top of the large square. Then, firmly press your knife on the lines to cut nine even squares.