Line two baking sheets with aluminum foil. On one sheet, lay out prosciutto slices and bake until golden, browned and beginning to shrivel, 12- 15 minutes. On the remaining sheet, arrange bread slices in an even layer. Drizzle with 2 tablespoons olive oil, season with salt and pepper, and toss to coat. Bake for 8- 10 minutes, or until bread is golden brown on the edges but still springy in the center. 

Meanwhile, make the blackberry sauce. In a small saucepan, whisk to combine 1 tbsp water with cornstarch. Add blackberries, honey and a pinch of salt and toss to coat. Bring to a boil over medium high heat, stirring constantly to prevent scorching, until berries have released their juice and mixture is fairly thick, about 3 minutes. Remove from heat and stir in apple cider vinegar. Let cool while you prepare the rest of the crostini.

Heat 2 tablespoons canola oil in a small skillet until shimmering. Add sage leaves in a single layer and cook until crisp, about 20 seconds. Transfer to a paper towel lined plate and sprinkle with salt. Repeat with remaining sage leaves. 

To assemble crostini, layer a piece of toasted bread with a crispy prosciutto slice. Top with a slice of burrata, spoon blackberry sauce over top and garnish with a few fried sage leaves. Repeat with remaining crostini. Enjoy immediately.