DIY Dry Brownie Mix

I put one batch, which makes a 9x13 pan, in a quart size jar.

For the jar:
1 1/4 c flour
1 tsp baking powder
1 tsp salt
2/3 c baking cocoa
2 c sugar

Then when I'm ready to bake, I put the dry ingredients in a bowl and add:
1 c butter (actually, I usually use 1/2 butter or oil and 1/2 applesauce)
3 eggs
1 tsp vanilla

I bake at 350 for 20-30 minutes...tonight it was 20, but they were in a jelly roll pan so they were thinner than usual.  These taste a whole lot like a boxed mix, but without all the preservatives and junk they add!