Bring cream, half and half, pumpkin, and vanilla almost to a boil, then remove from heat. Combine egg yolks and both sugars, and whip until pale yellow.

Slowly add hot cream to egg mixture to bring up to equal temperature, then combine all together. Strain and chill. 

 Heat oven to 325 and bake in a water bath for 1 – 1 ¼ hours or until a knife comes out clean.

Cool before serving.