Heat oven to 400°. Toss grapes with 1 tbsp thyme, the olive oil and 1/8 tsp salt. Place on a rimmed baking sheet; roast at 400° for 40 to 50 minutes, shaking a few times, until wilted.
Mix ricotta and remaining 1 tsp thyme and 1/4 tsp salt. Spread 1 generous tbsp on each crostino. Scatter grapes on top and garnish with more thyme, if using. Drizzle with honey.
Slice a 12 oz baguette into 24 pieces. Brush with 1 tbsp olive oil and bake at 400° for 8 to 10 minutes, until lightly toasted. Top with these three options.