Cheesy Green Bean Casserole

1 14-oz pkg frozen green beans
2 T. butter
1/4 cup diced onion
2 T. all-purpose flour
1 tsp. salt
1 tsp. sugar
1/2 tsp. garlic powder
3/4 cup sour cream
1 cup shredded cheddar cheese
1/2 cup crushed Ritz crackers ( or french-fried onions )
1 T. butter, melted

Cook green beans according to package directions.
Preheat oven to 350 degrees.
In lg. skillet, melt 2 T. butter over medium heat. Saute onion in butter until soft. Stir in flour and stir until smooth. Cook for 1 minute.  Stir in sour cream, garlic powder, salt, and sugar.   Add green beans and shredded cheese and stir to coat.

Transfer to greased 2-qt. casserole dish. Top with crushed crackers and drizzle with 1 T. melted butter ( or substitute french-fried onions - my kids like these )

Bake for 30 minutes at 350 until golden and bubbly.