If you need semisweet chocolate and all you have is cocoa powder you're in luck. For an equivalent of six ounces of semi-sweet chocolate mix together nine tablespoons of cocoa powder, seven tablespoons of sugar and three tablespoons of softened butter.
What do you do if your recipe calls for shortening and you don't have any? Replace it with butter or vice versa one cup equals one cup in baking!
No buttermilk? No problem! Simply stir together a cup of milk and one and three quarters tablespoons of cream of tartar. Or, one tablespoon of lemon juice for each cup of milk.
How about sour cream? Mix a cup of milk and a tablespoon of white vinegar and let it sit for five minutes, you're all set. No evaporated milk for the pumpkin pie? Try half and half it will work just as well!
Here is a little tip for your cooking timetable, don't save pie making until the end. Everything about pastry needs to be cold from the ingredients to the room so if you work on pies first you'll end up with flakier and tastier pies!