Preheat oven to 350°F. Generously butter 9x9x2-inch metal baking pan. Line rimmed baking sheet with parchment. Using on/off turns, blend first 4 ingredients in processor until coarse meal forms. Add pecans; using on/off turns, process until nuts are chopped. Add oats; process using on/off turns until mixture is moistened but not clumping. Press 3 1/2 cups crumbs onto bottom of prepared square pan (do not clean processor). Transfer remaining crumbs to lined baking sheet. Bake crumbs on sheet until golden, stirring once, about 12 minutes. Cool crumbs. Bake crust until golden, about 30 minutes. Remove from oven while preparing filling. Maintain oven temperature.
Blend all ingredients in same processor until smooth. Spread filling over warm crust; bake until set, dry in center, and beginning to rise at edges, about 20 minutes. Maintain oven temperature.