1In 10-inch skillet, cook bacon over medium heat, stirring occasionally, until crisp. Remove bacon with slotted spoon; drain on paper towels. Drain all but 3 tablespoons bacon drippings from skillet (if fewer than 3 tablespoons remain, add enough vegetable oil to drippings to equal 3 tablespoons).
2Add oil, onions, sugar, salt and pepper to drippings in skillet. Cook over medium heat 2 to 3 minutes, stirring occasionally, until onions are slightly softened. Stir in vinegar.
3Place spinach in very large bowl. Pour warm dressing over spinach; toss to coat. Arrange egg slices on top. Crumble bacon and sprinkle on top. Serve immediately.