Preheat oven to 425.
Prepare the orange syrup. Put all ingredients into a small pot and boil for about 10 minutes, until reduced. You’ll know it’s ready when the mixture has thickened and it sticks to a spoon. Remove from heat, and let it cool while you prepare the crostini.
Place baguette slices on a baking sheet, drizzle with a little olive oil, and season with salt and pepper. Toast in preheated oven for about 5 minutes, or until edges have browned.
To assemble each crostini, spread ricotta on each slice of bread and top with a few sliced pears. Then, drizzle the orange syrup, sprinkle with pistachios, and top with basil.