Stir together first 5 ingredients in a large mixing bowl; add flour and pecans, stirring until blended. Let stand 30 minutes or until mixture is firm enough to crumble into small pieces.
Spoon cake batter evenly into 2 greased and floured aluminum foil-lined 9- x 2-inch round cake pans. Sprinkle crumbled pecan mixture evenly over cake batter.
Bake at 350° for 45 to 55 minutes or until a wooden pick inserted in center comes out clean. Cool completely on wire racks.