Heat oven to 350°F. In large bowl, mix flour and granulated sugar. With pastry blender or fork, cut in 2/3 cup butter until mixture resembles fine crumbs. Stir in pecans. Press 1 1/4 cups crumb mixture in bottom of ungreased 9-inch square pan.
To remaining crumb mixture, add all remaining gingerbread ingredients; mix well. Pour evenly over crumb crust in pan.
Bake 40 to 50 minutes or until toothpick inserted in center comes out clean.
In medium saucepan, melt 1/2 cup butter. Stir in brown sugar and corn syrup. Heat to boiling. Cook about 1 minute, stirring constantly, until sugar dissolves. Stir in whipping cream; return to boiling. Remove from heat. Serve warm sauce over warm gingerbread. Top with ice cream; sprinkle with chopped pecans.