How to Make It
Combine first 4 ingredients in a large bowl; toss well.
Combine vinegar, sugar, juice, mustard, salt, and pepper in a small saucepan. Bring to a boil over medium heat; cook 1 minute. Remove from heat, and stir in sour cream. Drizzle warm dressing over spinach mixture; toss well. Sprinkle with bacon; serve immediately.