Grilled Nectarines with Honey-Balsamic Glaze

1/2 cup plus 2 tablespoons honey
1/4 cup balsamic vinegar
1/2 teaspoon vanilla extract
1 8-ounce container crème fraîche
6 firm but ripe nectarines, halved, pitted

Whisk 1/2 cup honey, vinegar, and vanilla in small bowl. Whisk crème fraîche and remaining 2 tablespoons honey in medium bowl to blend. (Glaze and crème fraîche mixture can be made 1 day ahead. Cover separately. Refrigerate crème fraîche mixture. Re-whisk both before using.)

Prepare barbecue (medium-high heat). Brush nectarines generously with half of glaze. Grill until heated through, turning occasionally, about 4 minutes. Arrange 2 nectarine halves, cut side up, on each plate. Drizzle with remaining glaze. Spoon some crème fraîche mixture into center of each nectarine half and serve.