As the oven heats, pour the balsamic vinegar into a pot, and heat it to medium-high. The liquid should reduce to half its original volume (after about 10 minutes). Stir occasionally. It should be a bit thicker and syrupy. Set aside.
Finely chop the turkey bacon and cook for 4-5 minutes, or until lightly crispy and thoroughly cooked. Set on a plate lined with paper towels to drain off any excess grease.
Place the onions in the frying pan and splash with a little balsamic vinegar. Saute the onions until they're translucent, about 2-3 minutes.
Spread goat cheese on each piece of flatbread. Top with the grilled onions, crumbled bacon and cranberries. Heat it in the oven for 4-5 minutes, or until the goat cheese has melted. Drizzle with balsamic vinegar syrup.
Recipe by Collegiate Cook at https://collegiatecook.com/2014/12/01/turkey-bacon-goat-cheese-flatbread/