To make buttermilk, add 2 teaspoons of white vinegar to milk and let sit for about five minutes. The milk with thicken, just like buttermilk.
If using the cake at a later time, refrigerate before baking. I also sometimes make this ahead and freeze before baking. Allow the cake to defrost in the refrigerator before baking.
Some members of our family love this cake served with a pat of butter on top. Yum!