Heat oven to 325°F. Grease 6 (6-oz) ramekins or custard cups with butter; place in 13x9-inch (3-quart) glass baking dish. In large bowl with wire whisk, beat egg yolks about 1 minute or until slightly thickened. Beat in sugar, cream, pumpkin and pumpkin pie spice until smooth. Divide mixture evenly into ramekins.