Heat gas or charcoal grill. Remove pie crusts from pouches; unroll on work surface or cutting board. With pizza cutter, cut each crust into 4 equal pieces.
In medium bowl, beat cream cheese and 3/4 cup sugar with electric mixer on medium speed until smooth. Add egg, flour and 3 teaspoons of the cinnamon; beat until combined.
Divide cream cheese mixture evenly among crust pieces. Fold crust over filing; press edges firmly with fork to seal. Brush tops of pies with whipping cream. In small bowl, mix 1 1/2 teaspoons sugar and remaining 1/2 teaspoon cinnamon; sprinkle over tops of pies. Cut 2 slits in top of each pie.
Spray sheet of heavy-duty foil with cooking spray; place foil, sprayed side down, on top grill rack over low heat. Place pies on foil. Cover grill; cook 20 minutes or until pies are golden and fully cooked.