Can You use olive oil instead of vegetable oil to cook brownies?

I have and it tasted just fine.

If you're determined to use olive oil, I wonder if it would work if you used light olive oil, which has a lot less taste than EVOO?

I've done this twice. The first time I also added a little orange extract and people went nuts over the brownies - everyone asked for the recipe. The second time I just did the evoo with no orange and it bombed. I guess the orange masked the olive flavor and complimented the chocolate well - without it it just tasted off.

You'll be able to taste the olive oil, which is not usually what I'm going for with brownies.