In a lidded jar, combine the oil, vinegar, sugar and mustard. Season with salt and pepper; shake well and refrigerate.
Cook bacon in a skillet until crisp; drain and crumble. Cook almonds in 1 T. bacon grease, shaking over high heat until almost browned.
Combine the spinach, apples, green onions, bacon, and almonds in a large salad bowl and toss with the dressing; serve.