How to Make It
In a small saucepan, combine the milk, cream and vanilla bean and seeds and bring to a boil. Cover and remove from the heat. Let stand for 5 minutes. Discard the vanilla bean.
Meanwhile, in a small bowl, sprinkle the gelatin over the water and let stand until softened, about 5 minutes.
Whisk the gelatin into the hot milk, then whisk in the sugar, yogurt, crème fraîche and the 1/4 cup of rose syrup.
Brush four 1/2-cup ramekins very lightly with vegetable oil. Pour the panna cotta mixture into the ramekins and refrigerate until firm, at least 5 hours.
Run a small knife around each panna cotta, then dip the ramekin bottoms in hot water and pat dry. Invert the ramekins onto small plates. Holding both the ramekin and the plate, give each plate a firm tap on a counter to release the panna cotta. Remove the ramekin. Drizzle the panna cotta with rose syrup, top with rose petals and serve.
Chef Erin Eastland loves using imported Italian rose syrup. Her favorite one is Organic Rose Syrup (Sciroppo di Rose), produced by Azienda Agricola Magliano; it's available at divinepasta.com and at specialty-food stores.