Turn on the oven's broiler and move a rack so that it is about 6 inches under the heat. Lightly coat a baking sheet with nonstick spray or olive oil.
In a small bowl, combine the red onion and vinegar (add more vinegar if needed to cover the red onion). Set aside.
Cut the figs in half and place them cut-side up on the baking sheet. Combine the sugar and cinnamon and sprinkle a bit over each fig. Place under the broiler until lightly caramelized, about 4 minutes (watch them closely to be sure they don't burn). Set aside to cool.
Place a large skillet over medium-high heat. Add the oil and bread cubes and toast, stirring often, until bread is golden brown and very crisp. (This should take 6 to 10 minutes, depending on how thick and how fresh the bread is.) In the last couple minutes of cooking, drizzle with a bit more oil and add salt and a generous amount of black pepper.
To make the vinaigrette, whisk together the balsamic vinegar, honey and mustard. Add the oil while whisking. Season with salt and pepper, to taste.
To serve, drain the liquid off the red onions. Top lettuce with red onions, croutons, figs and goat cheese. Drizzle with vinaigrette just before serving.