I was thinking about this the other day-- how I think that you should always have on hand the means to make three things when the mood hits you:
Cinnamon Sugar: (for cinnamon toast and to shake liberally onto baked sweet potatoes) Mix 1 Tbsp of cinnamon with 1/2 cup sugar and keep in empty cinnamon spice jar. Refill as needed.
Chocolate Chip Cookies
The ingredients for these items would include things like flour, sugar, brown sugar, sticks of butter, chocolate chips, confectioners sugar. I make sure to always have these things on hand, ready and waiting, on a special shelf in my pantry I think of as my baking shelf.
I think it's very telling that the things I want to be able to make are all sweet. I wish I kept the makings for salad just as ready.