Mix together all dry ingredients: the flour, sugar, baking powder, and baking soda. In a separate bowl, mix together all wet ingredients: the sour cream, eggs, and vanilla. Now mix the dry ingredients into the wet ingredients. Mix thoroughly. Should be a slightly sticky dough texture. Add the raisins to taste. My family likes a lot of raisins, so I put in enough so that there's a raisin in almost every bite! Bake at 325 degrees for about 1 to 1 1/2 hours, or until skewer comes out clean.