Pre-heat oven to 325°F.
Coat a large glass baking dish with cooking spray.
In a medium bowl, stir grapes, oil, salt, thyme and pepper.
Spread out in one layer in the baking dish.
Roast, stirring occasionally until wrinkled and caramelized, 48 to 55 minutes.
Remove from the oven.
Drizzle balsamic vinegar over the grapes, and stir to coat; set aside.
Spread goat cheese on the baguette, dividing equally.
Top with the grape mixture.
Sprinkle with walnuts and drizzle with honey.