Preheat oven to 350 and line and 8x8 pan with parchment papers
Mix wet ingredients in one bowl and dry in another
Add wet ingredients to dry mixture and stir well
Transfer to the baking dish and smooth down top into an even layer. Sprinkle chocolate chips and or nuts on top if using.
Bake on the center rack for 30 min. The edges should look slightly dry and a toothpick should come out mostly clean. Remove from oven and let cool for an hour.