So I thought I make a list of alternatives for some ingredients you can use for baking or cooking:
Alternative for Buttermilk
Buttermilk is common here in Germany and is really cheap. But one time I was planning to make a Marble Cake and my recipe calls for buttermilk. Only then did I find out that I forgot to buy one!!!
What I did was I used 1 cup of milk (Full or Fresh will do) and squeezed a half of a lemon into it. After some seconds or minute, the milk started to thickens. It is really the same consistency and taste of a Buttermilk.
Substitute for Cake Flour
I usually just use regular flour when baking, but then I came across a recipe once that requires to use cake flour. So my husband and I went to all grocery stores and supermarket to look for one...but, for a place where everyone bake, it is really difficult to find baking supplies and stuff around where we live, in short, we did not find any.
So I consulted Mr. Google for what can I use as substitute. I found that for every cup of Cake flour you just replace 1 Tbsp of flour with 1 Tbsp of Cornstarch. So easy!!!
(Note to readers: This list is a work in progress as I will be adding more ingredient alternatives whenever I happen to come across one that I have personally tested.)