In a large bowl, whisk together the olive oil, red wine vinegar, chopped shallot, capers, Dijon mustard, and minced garlic until well combined.
Add the chopped tomatoes, peaches, basil, and thyme. Gently toss until everything is evenly coated with the dressing.
Season with salt and pepper to taste. Cover and refrigerate for about 1 hour to allow the flavors to meld together (optional).
Just before serving, place sliced sourdough baguette on a baking sheet and spray with cooking spray. Place under the broiler just until golden and crisp, then flip each over and repeat.
Spoon the peach and tomato mixture over the toasted bread and serve immediately.
Notes
Use ripe but still firm peaches so they hold their shape.
Roma or vine-ripened tomatoes work well because they aren't overly watery.
The bruschetta mixture can be made up to 4 hours in advance and stored in the refrigerator.
Wait to spoon the mixture onto the bread until serving so the baguette stays crisp.