Combine the following until crumbly:

1 3/4 cup dry oatmeal
1 cup brown sugar
1 cup margarine
1 3/4 cup flour
1 tsp. soda

Pack in a 9x13 pan, reserving 1 cup for the top.  Bake 15-20 minutes at 350ºF.  Combine the following and microwave to a boil, stirring frequently:

2 cups raisins (plumped with 1/2 cup water)
4 egg yolks (beaten)
1 1/2 cups sugar
3 Tbsp. cornstarch
2 cups sour cream
pinch of salt
1/2 tsp. cinnamon
1/4 tsp. nutmeg
1 tsp. vanilla

Pour into crust.  Sprinkle remaining crust over.  Bake an additional 5-10 minutes at 350ºF.