For Cupcake Batter: Gently stir 15 oz. cookie pieces into cake batter. Divide mixture among mini cupcake pans prepared with cooking spray to create 144 cupcakes. Bake as directed on package. Cool completely in pans on wire racks. Remove from pans.
Divide buttercream icing evenly among 3 bowls.
For Birthday Cake Cupcakes: Stir food color into 1 bowl of icing until well blended. Spoon icing into pastry bag fitted with round tip. Pipe a mound of pink icing onto 48 of the baked cupcakes. Garnish each with a piece of chopped cookie and a dusting of glitter sprinkles.
For Butter Pecan Salted Caramel Cupcakes: Stir butter pecan syrup into second bowl of icing. Spoon icing into pastry bag fitted with French star tip. Pipe icing onto 48 of the remaining cupcakes, leaving a small circle open in the center. Fill centers with 1/4 tsp. salted caramel sauce. Top each cupcake with a pecan half and a piece of chopped cookie.
For Pineapple Cupcakes: Heat sugar in heavy saucepan on medium-low heat until well caramelized. Add pineapple and swirl pan. Caramel will harden at first but then start to dissolve from the pineapple juices. Continue to cook and stir 3 to 5 min. or until caramel has softened and pineapple pieces are evenly caramelized. Cool completely.
Reserve 48 pineapple pieces for garnish; finely chop remaining pineapple and stir into remaining third of the icing. Spoon icing into pastry bag fitted with star tip. Pipe a rosette onto remaining 48 cupcakes. Top each with 1 reserved pineapple piece. Finely chop any remaining cookie pieces. Place around the top edge of each cupcake.
For each serving, plate one of each cupcake flavor on a serving plate.