Cook penne in boiling water seasoned with garlic and salt. Do not overcook. Drain and place in well-greased casserole dish. Cool slightly and add 2 beaten eggs and parsley. Mix well. Melt butter in saucepan and saute onions and celery until wilted. Stir in cream and cook on medium heat until blended. Slowly add cheeses (reserve one cup cheddar) while stirring constantly until melted. Season with salt, white pepper and hot sauce. Pour ovefr penne and mix well. Top with 1 cup grated cheddar. Bake at 350 for 35-45 minutes, until cheese is melted and barely starting to brown.Once browning starts it will brown fast. Do not burn.