1Heat oven to 375°F. Remove pie crusts from pouches. On lightly floured surface, unroll and stack crusts one on top of the other. Roll to 17x12-inch rectangle. Fit crust into ungreased 15x10x1-inch pan, pressing into corners. Fold extra crust even with edges of pan. Crimp edges.
2In large bowl, mix brown sugar, cornstarch and lemon juice. Stir in peaches to coat. Spoon mixture into crust-lined pan. Break cookie dough half into coarse crumbs; sprinkle evenly over filling. (Wrap and refrigerate other half of cookie dough for another use.)
3Bake 55 to 60 minutes or until crust is golden brown and filling is bubbling. Cool on rack 45 minutes. Cut and serve.