To prepare crust, lightly spoon flour into dry measuring cups; level with a knife.
Heat a nonstick skillet over medium-high heat.
Add flour to pan; cook 5 minutes or until light brown, stirring often.
Remove pan from heat.
Transfer flour to a bowl; cool completely.
Combine cooled flour, 1/2 cup brown sugar, and salt in a food processor; pulse 5 times or until combined.
Add chilled butter; pulse until mixture resembles fine meal. Press 1 cup of flour mixture evenly into the bottom of a 13 x 9-inch baking dish coated with cooking spray; reserve the remaining flour mixture.
Bake at 350 for 10 minutes or until crust is lightly browned.
To prepare filling, spread pumpkin in an even layer on several layers of paper towels; cover with additional paper towels.
Let stand 5 minutes.
Combine granulated sugar, 1/2 cup dark brown sugar, and cream cheeses in a bowl. Beat with an electric mixer at medium speed 2 minutes or until smooth. Scrape pumpkin into bowl using a rubber spatula.
Add egg substitute, cinnamon, vanilla, allspice, and egg; beat until smooth. Scrape batter into baked crust.
Combine reserved flour mixture and pecans in a small bowl; sprinkle with 2 teaspoons water. Squeeze handfuls of topping to form large pieces. Crumble over filling.
Bake at 350 for 40 minutes or until filling is firmly set.
Remove from heat; cool in pan on wire rack to room temperature.
