Whisk canola oil, sugar, water, balsamic vinegar, and seasoning packets from ramen noodles in a bowl until thoroughly combined and sugar and seasoning packets have dissolved.
Toss ramen noodles in a large salad bowl with broccoli slaw mix and green onions. Pour dressing over the salad and let stand 1/2 hour to 4 hours – shorter for crunchier noodles, longer for softer ones. Just before serving, toss salad again with cashews and sunflower seeds.