Combine flour, brown sugar, pecans and butter and pat on bottom only of a 9 x 13-inch pan. Bake at 375° for 15 minutes. Cool completely. Combine cream cheese, Cool Whip and powdered sugar, whip until fluffy. Spread over cooled crust. Combine pudding and milk; whip until thick. Spread over the cream cheese mixture. Spread the rest of the big container of Cool Whip over the pudding mixture. Sprinkle toasted pecans or almonds over top. Chill.