1. Heat oven to 325 degrees . Season chicken pieces with 1/4 teaspoon of the salt. Heat oil in a Dutch oven over medium-high heat. Brown chicken in two batches, 3 to 4 minutes per side (12 to 16 minutes total). Remove to a plate, keeping as much oil in the pan as possible.
2. Reduce heat to medium. Add onion and red pepper; cook 3 minutes to soften slightly. Mix in flour, sweet and smoked paprika, and cayenne pepper. Cook 2 minutes, stirring constantly. Add broth, tomatoes and remaining 1 teaspoon salt. Bring to a boil and simmer 3 minutes to thicken. Add browned chicken back to pot, ladling a bit of sauce on top. Cover and bake at 325 degrees for 45 minutes or until chicken is very tender.
3. Remove chicken; cover to keep warm. Add sour cream to a bowl; whisk in a cup of the hot sauce to temper. Whisk sour cream mixture back into pot. Serve two pieces of chicken over cooked spaetzle with several spoonfuls of sauce. Garnish with parsley, if desired.