Step 1

Preheat oven to 350F.

Step 2

Add raisins to a bowl. Pour hot water on top and let soak for 10 minutes. Drain and set aside.

Step 3

In a large bowl, mix together butter, brown sugar, baking soda, oatmeal and flour. Put half of the mixture in a greased 9x13 baking pan. Bake for 7 minutes.

Step 4

Add egg yolks, cornstarch, sugar and sour cream to a medium pot on the stove over medium low heat. Cook for about 8 to 10 minutes, stirring constantly. Add raisins and vanilla and stir. Pour mixture over crust.

Step 5

Top with remaining oat mixture. Bake for 40 minutes. Let cool before cutting into squares.