Preheat oven to 325°. In a large saucepan, heat whipping cream and cream until bubbles form around side of pan; remove from heat. In a bowl, whisk egg yolks, 1 cup sugar, extract and salt until blended but not foamy. Slowly stir in hot cream mixture., Place an ungreased broiler-safe 13x9-in. baking dish in a baking pan large enough to hold it without touching the sides. Pour egg mixture into dish. Place pan on oven rack; add very hot water to pan to within 1 in. of top of dish. Bake until center is just set and top appears dull, 40-50 minutes. Immediately remove dish from water bath to a wire rack; cool 1 hour. Refrigerate until cold., Mix brown sugar and remaining 1/3 cup sugar. To caramelize topping with a kitchen torch, sprinkle custard evenly with sugar mixture. Hold torch flame about 2 in. above custard surface and rotate it slowly until sugar is evenly caramelized. Serve immediately or refrigerate up to 1 hour., To caramelize topping using a broiler, let custard stand at room temperature 30 minutes. Preheat broiler. Sprinkle custard evenly with sugar mixture. Broil 3-4 in. from heat until sugar is caramelized, 2-3 minutes. Serve immediately or refrigerate up to 1 hour.