Season beef lightly with dried onion, garlic powder, and black pepper. Heat a large skillet over medium-high heat. Cook and stir meat in the hot skillet until browned and crumbly, 5 to 7 minutes. Drain and discard grease.
Fill a large pot with lightly salted water and bring to a rolling boil. Stir in egg noodles and return to a boil. Cook noodles uncovered, stirring occasionally, until tender yet firm to the bite, about 6 minutes. Drain.
Combine water and bouillon cubes in a microwave-safe measuring cup. Cook in the microwave until boiling, about 6 minutes. Crush cubes and stir broth until dissolved.
Pour broth into a deep saucepan over medium-high heat. Add flour gradually, whisking in until bubbly and thick, about 1 minute. Reduce heat and add sour cream, ketchup, and vinegar. Whisk until smooth, about 1 minute. Add beef and cook until heated through, about 5 minutes more. Pour beef sauce over noodles and toss to coat.