Melt 2 tablespoons butter in a large skillet over medium-high heat, and cook the onions until soft (3-5 minutes)
Add half the apple cider vinegar, cooking until the cider has mostly evaporated. Add the remaining cider and cook another 5 minutes or until the onions are golden and caramelized.
Add the thyme, and a pinch of salt and pepper and remove from the heat.
If you are adding the prosciutto, cook in a skillet over medium heat until crisp, and remove from the skillet.
Brush the outside of each slice of bread with olive oil. Inside, layer the cheese, onions, prosciutto and a generous sprinkle of Organic Cacao Apple Crisp.
In a skillet over medium-high heat, melt the remaining butter and fry each sandwich until golden, about 3-5 minutes per side.
