For the pears: Heat one liter of water, 250 grams of sugar, the scraped vanilla pulp and the vanilla bean, stirring until the sugar is dissolved. Cut the pears in half, remove the skin, sprinkle them with a little bit of lemon juice and cook them in the vanilla syrup for about six to eight minutes at low temperature until soft. Remove from the heat and cool in the syrup. Lift the pears out of the syrup, remove the core with a small spoon and score the pears in a fan shape. Place on a baking sheet lined with aluminum foil, press apart a tiny bit, and sprinkle with the remaining sugar. Use the pear syrup elsewhere. Before serving, caramelize the pears under a heated oven broiler until the edges are browned.