Pulse sugar and lavender together in a food processor or spice grinder.
Preheat oven to 425°F and butter the inside of a 4 quart stoneware casserole.
Peel, halve and core the pears, then toss with 3 tablespoons of the lavender sugar. Lay the pears cut side down in the stoneware baking dish, cover with lid and bake for 20-30 minutes until just barely soft. Remove from oven and remove the lid.
Preheat the broiler. Turn pears cut side up and sprinkle each pear with 1/2 teaspoon lavender sugar, then place 6 inches under the broiler and cook until caramelized, about 4 to 5 minutes.
Serve pear halves with fresh raspberries, crème fraiche and drizzled with honey. Sprinkle with fleur del sel if desired.