Combine cream, walnuts and walnut oil in large saucepan over medium heat. Heat to 200° F. Remove from heat and let stand 20 minutes to allow infusion of walnut flavor. Strain through a fine mesh strainer and keep warm. Discard walnuts.
Beat egg yolks, sugar and vanilla in a mixing bowl until pale and thick. Strain through a fine mesh strainer. Gradually pour cream into egg mixture, whisking until combined.
Pour mixture into 15 6-ounce ramekins. Place ramekins in a large baking pan; pour boiling water into the pan to halfway up sides. Bake at 300° F about 50 to 60 minutes, or until custard is just set. Remove from oven and set ramekins on a rack to cool slightly. Transfer to refrigerator for at least 4 hours.
Place walnuts in a small dry skillet over medium heat. Stir a few minutes until fragrant.
Stir maple syrup into walnuts and cook until well coated and syrup is absorbed, 1 to 2 minutes, stirring constantly. Transfer to parchment paper-lined tray to cool. Dust lightly with icing sugar.
Just before serving, sprinkle 1 tablespoon sugar on each ramekin. Using a kitchen torch or oven broiler, brown and caramelize sugar. Immediately top with a glazed walnut.