Preheat oven to 350 deg. In a large mixing bowl combine cake mix, pumpkin pie mix, and 2 eggs... Mix at LOW speed untill moistened then at med. speed adding remainder eggs and topping mix. Mix at low speed untill moistened then at med. speed for 3 min. Pour into greased and floured cake pans and... Bake 45 to 50 min OR untill wooden pick comes out clean Cool 15 min... remove from pan(s) and cool completely. FROSTING: Cook milk and flour until thick; cool in fridge. Beat butter, sugar and vanilla with mixer. Add flour and milk mixture a little at a time (make ahead of cake so that it has plenty of time to cool). Beat well.