Preheat oven to 400. In a small bowl mix together marinara sauce, sour cream and 1 oz of the goat cheese. Pour into oven safe baking dish, crumble remaining goat cheese on top and bake for 30 minutes, until you can see the edges slightly bubble and some tips of the cheese turn brown. Remove from oven and allow to cool for 5-10 minutes before serving. Serve with crackers of garlic crostini.