Preheat oven to 350°F. In bowl of a food processor, combine pumpkin, praline liqueur, milk and cream. Blend until pumpkin is well puréed and blended into the milk mixture. Once well blended, strain through a china cap or fine mesh strainer to remove excess pulp, making sure all liquid is extracted. Return liquid to bowl of food processor and add eggs, egg yolks, sugar, cinnamon, nutmeg and vanilla. Pulse 1–2 minutes to thoroughly dissolve sugar. Pour ingredients into a mixing bowl, whisk thoroughly and adjust sweetness and flavor if desired. Pour mixture into 8 ramekins or 1 large flan mold. Place cups or mold into a baking pan with 1-inch lip. Carefully pour approximately ½ inch of water into bottom of baking pan. Place pan on center rack of oven. Bake 45 minutes to 1 hour for ramekins or 1½ hours for flan mold. Insert a tester into custard to ensure that it has set properly. Custard is best when chilled overnight. Note: You may wish to pour caramel into the bottom of each ramekin. If so, place 1½ cups sugar with ¼ cup water into a 9-inch sauté pan. Place over medium heat, swirling the pan occasionally as sugar melts. Do not stir mixture with a spoon, only swirling pan as caramel browns to mix ingredients and to keep from burning. When all sugar is dissolved and a caramel color is achieved, quickly pour an equal amount into each ramekin.