Mix flour, butter and 1/2 C nuts and press into 9x13 pan. Bake at 350 degrees for 15 minutes. Cool thoroughly. Meanwhile: Combine cream cheese and powdered sugar and spread on crust. Spread 1/2 container of Cool Whip next. Beat instant puddings and milk together for 2 minutes. Let set for a few minutes until firm enough to spread on first layer. Spread the other half container of cool whip on the second layer. Garnish with pecans. Let stand a few hours before cutting.
Other variations are butterscotch, chocolate or pumpkin pudding in place of the lemon.