Preheat oven to 350F. Prepare pans (muffin, bread, etc.. ) with a coating spray or whatever your secret non-stick product is. I won't share mine just yet. Sorry.
Mix dry ingredients (Flour, baking soda, baking powder, salt and rosemary)
Whisk eggs until frothy. Whisk in sugar. Whisk in melted butter and olive oil. Stir in lemon zest and zucchini.
Now I like to use a separate bowl and add 1/3 of the dry mix, then mix in 1/2 of the wet, then 1/3 of the dry then the other 1/2 of the wet and then the last 1/3 of the dry. I guess I could have just said to alternate dry and wet, starting and ending with dry. But that wouldn't have been as much fun for you to read, now would it?
Put into prepared pans. Bake for awhile. It will vary depending on what kind of pan you have. Muffins usually take around 20 minutes, where loaf pans take almost an hour. So, just check it. I have decided that when I start to smell what I'm baking pretty heavy in the house, then it's almost done. When you press gently on the top, it should bounce back. At least that's what they say. I've never seen any baked good "bounce". Video it for me if it does. That would be something to see.