Preheat oven or grill to 450F.
Add the ricotta to a food processor and blend until smooth and creamy, around 2 minutes total. Transfer to a piping bag and set aside.
On a sheet pan, combine the grapes, 2 tablespoons olive oil, balsamic vinegar, ¼ teaspoon flakey salt, and 4 sprigs fresh thyme leaves. Toss the grapes to coat and roast, flipping halfway, until they are soft and caramelized but still plump and intact, 15 to 20 minutes. Remove the grapes from the oven and set aside.
Drizzle both sides of the bread slices with olive oil. If using a grill, place the bread over direct medium heat and cook until golden brown on both sides. If using the oven, place the bread on a sheet pan and cook until golden brown on both sides.
Transfer the bread to a serving platter. Pipe the whipped ricotta over each slice of bread and top with the roasted grapes. Garnish with a drizzle of honey, pinch of flakey salt, drizzle of olive oil, and a few fresh thyme leaves. Serve immediately.