COMBINE 4 lb. of the OREO Pieces (or 1 lb. for the trial recipe) and butter; press evenly onto bottoms of 4 parchment-lined half-sheet pans (or 1 prepared half-sheet pan for trial recipe).
PLACE cream cheese and sugar in large bowl of electric mixer fitted with paddle attachment. Beat on medium speed until well blended. Add eggs, 1 at a time, beating just until blended after each addition. Fold in blueberries. Pour evenly over crusts. Sprinkle batter in each pan with 1/2 cup of the remaining OREO Pieces.
BAKE in 350°F-standard oven for 45 to 50 min. or until cheesecakes are almost set in centers. Cool completely; cover. Refrigerate 4 hours or overnight.
DRIZZLE chocolate evenly over cheesecakes. Cut dessert in each pan into 32 bars. Store in refrigerator.