Preheat oven to 350 degrees F. Spray a 13 x 9" baking dish with cooking spray. Set aside.
Drain sauerkraut in a strainer and rinse for about 30 seconds with water. Press it against the sides of the sieve with a spoon to remove excess water. It doesn't need to be dry, just not dripping.
In a large bowl, stir sauerkraut, brown sugar and caraway seeds until combined.
Spread sauerkraut mixture evenly in prepared baking dish.
Scatter onion slices over sauerkraut.
Separate gnocchi and place evenly over onion layer.
Arrange sausage slices over gnocchi.
Pour 1/2 cup water over the entire dish. Cover tightly with foil and bake for 40-45 minutes.