Preheat oven to 375 and prepare a baking sheet with cooking spray.
Heat oil in a large sauce pan. Add garlic, salt and pepper and cook over low heat for 1-2 minutes.
Add onions and cook over low heat for 15 minutes, until onions soften and become translucent.
Stir well and cook for another 10-15 minutes until onions turn light brown.
While onions are cooking, place butternut squash in oven and roast for 15 minutes until they start to soften.
Add mushrooms and cook for another 5-10 minutes.
Top flatbreads with roasted butternut squash, mushrooms and caramelized onions.
Add burrata cheese all over the flatbread.
Top with cranberries and sage.
Place back into oven for 5-10 minutes until flatbread gets crispy on the bottom.
Notes
To store: Wrap in parchment paper and place in a plastic bag in the refrigerator for up to 4 days.To reheat: Place on a baking sheet and bake for 10-15 minutes at 350 degrees F.