Personally, I don't see why not, but I look forward to other responses. To me, muffins are a quick bread in muffin form, and lots of quick breads use oil.

I know that some of my muffin recipes and even cake ones call for oil. I've had good luck with olive oil in other muffin recipes, like lemon ones. Also, this is not EVOO, this is the kind of olive oil that is made for baking so does not have a very strong taste at all.

I did some checking since I thought I remembered something about using less oil than melted butter. See if any of this helps.

"...use 10-15% less oil than the amount of butter called for (oil is 100% fat while butter has some water and milk solids in it, so using the full amount may result in a greasy or too-gooey outcome). Sometimes—when making brownies, for example—I get the best texture by adding a little water to the recipe to replace the water that was in the butter."

Or...

https://www.marthastewart.com/8044756/how-when-substitute-olive-oil-butter-baking

Oil and solid fats do not behave the same in baking. Find a recipe that calls for oil ti ensure success. What about this recipe makes you want to try it? You are already wanting to modify it, so why do you want to try it? Obviously the recipe depends on the taste of butter or margerine and if you sub olive oil you will have compeletly changed the recipe.

I sub extra virgin olive oil for butter in many baked items. It gives a buttery taste too, IMPO. Nobody has ever noticed anything off about my banana bread. I usually use half butter/half olive oil in that - and I usually make it into muffins rather than a loaf too. On the contrary, everybody who's eaten it says it's delicious.

I also use it for pastry crusts, sometimes combined with butter.

P.S. I think a pinch or so of nutmeg adds a buttery flavor, so you might try that. I do it often.

Cakes tolerate oil pretty well, so muffins should be good. I agree with Linda, however, about starting with a successful recipe. You can use the flavors of the recipe you want to try with a base recipe you know works. Unless it's weird... like has boiling water or frozen molasses or something really odd for which following exactly is essential. For me, however, I'd make the recipe as written first, to know what it was supposed to be like, before messing with it. Muffins are pretty hard to ruin, however, so you could just go for it, and adjust for whatever flaws you end up with next time. Good luck!

P.S. Never ever use oil in cookies unless specifically called for.

The reason I want to make THIS recipe, is that something I do routinely is dip into my late mother's recipe folder and pull out and make one of the recipes she clipped. She was an inveterate recipe clipper and saver, although she didn't use many of them since my Dad was such a picky eater. So as a way of honoring her, I make the recipes she dreamed of but never had a chance to try. If they are good I save them, if they are "meh" or bad I throw them out. It's a way for me to feel close to my deceased mother and to pare down and it is a little bit of fun.

I made the muffins for breakfast.

If it had been softened butter in the instructions, or if it said to cut in the butter, I would have used the butter, but since I am on a diet and also trying to lower my cholesterol, no sense using butter if it isn't really necessary and won't make that big of a difference. So that's why I posted the question, for discussion purposes. If I had used another recipe, then there would be no post of mine here on the CF regarding that subject.

The muffins were good, nothing special, very flavorful though. I did not notice anything negative that would relate to the oil substitution. The recipe came from Sun Maid. Hubs thought they were a little too sweet. Not me. I have an oatmeal raisin muffin recipe I like better, and I could always add chopped apple to that, so not sure if I'll make these again. The other odd thing is the recipe only made 11 muffins and I didn't fill the cups all that much. They were regular sized, even a tad small.

Here's the recipe and my notes.

Sun Maid's Raisin Apple Muffins

1 1/2 cups all purpose flour (I used 1 cup whole wheat pastry flour and 1/2 cup AP)

1/2 cup sugar

2 tsp. baking powder

1 tsp cinnamon (I used 3/4 and that was PLENTY)

1/4 tsp. salt

(My addition: 1/4 tsp. nutmeg. That was OK but I wouldn't do it again, it competed with the vanilla and was a little too much going on.)

1/2 cup butter or margarine, melted (I used 1/3 cup sunflower oil, I was out of olive oil)

1/4 cup milk

1 egg beaten

1 tsp. vanilla

1 cup peeled tart green apple, chopped (I used a gala apple 'cause that's what I had)

1 cup raisins (the recipe says baking raisins, but I don't even know if they sell those anymore. I used 2/3 cup raisins and they were PLENTY. I soaked them a bit in the wet ingredients.)

Preheat oven to 400. Grease or line 12 muffin cups (I only got 11 muffins out of the batter)

Combine dry ingredients and whisk together. Combine wet ingredients and mix well. Add wet ingredients to dry ingredients and mix until just moistened. Stir in apple and raisins. Spoon into prepared muffin cups.

Bake at 400 for 20-25 min. until toothpick inserted in the center of a muffin comes out clean. (Note: in my oven, 22 min. was a tad too long) Place pan in the upper third of the oven. Makes 12 but IMHO, that would be quite small.

Ya know, that was the whole point of my post, I never wanted to follow the recipe, I'm no recipe pedant, I wanted to discuss what the effects on ANY recipe would be of subbing olive oil or some other oil rich in unsaturated fats, in a muffin or other similar baked good . . . And as far as evaluating it, well I could just make it and evaluate it all on my own, no need to post on the CF at all.

Oh! Well, you got the answer for the oil question. It sounds like you had a good result.

So, on that theme, I have a few touchpoints. I learned to make cakes out of whatever, when they were the only sweets we had (muffins structurally being cakes). Sometimes, the only fat I had was oil, but I wasn’t using recipes. The rule is if it looks like cake batter, tastes like cake batter, and you didn't forget to put in some baking powder, it's a cake. So with whichever fat, one adjusted as needed. I might put in an extra egg for the water, richness (it was low viscosity cooking oil, not olive) and structure (glue). Muffins, being smaller and weighing less are more tolerant.

Early in my time having to do all the Passover cooking by myself, I learned that the kind of fat doesn't matter for the structure in the matzah balls. I think it was Cloudswift who explained that the relative amount of fat was small enough that it just didn't make a difference if it was a couple tablespoons of schmaltz or oil, making vegan easy (though the flavor part requires adjustment). Of course, with dumplings of any kind, the biggest difference is in how they're cooked, whether they become fluffy or leaden or chewy.

A group of us were making cookies en masse for a fundraiser, and when we ran out of solid fat, one of the gals subbed oil in a couple of recipes. They ran all over the pans in puddles. If they'd been contained, like in a muffin pan, they might have been okay, but there was nothing to hold them together on sheet pans. Drop cookies are meant to spread and flatten as the fat melts, but with oil, which is already liquid, they just spread and spread. Cut cookies are drier and not supposed to spread, though eggs and/or baking powder will make them puff, which means they get a little bigger sideways, too. They set their shapes pretty quickly, before the fat melts. Oil substitute (there may be recipes developed using oil that work better), while better than in drop cookies, again, spreads too fast for the shapes to set.

In enriched breads, for the most part, it's like the matzah balls--too small a percentage to make much difference. I prefer solid vegetable shortening (which I usually hate) or baking sticks (“vegan butter”). Butter in the same proportion is too rich and makes the crumb heavy, and almost greasy-seaming. I'm sure that could be adjusted. I've only used olive oil in pizza crust, but EVOO (in quantity similar to enriched bread, not a spoonful) does give the kind of butteriness you spoke of, without being heavy,. For regular breads, lighter oil works fine, but one uses less. Since the liquid in bread is adjusted by feel, depending on how damp the flour (and air) are, I don't know if there's a specific compensation. Many enriched bread recipes call for oil to begin with. One could check the proportions in a few to make a good estimate of how much to substitute for solid fat. I recently made a recipe that called for oil, where I thought the crumb could be more tender, but I think the recipe was meant to be easy to remember, with no fractions, rather than optimized for the best loaf.

I hope some of this is what you were looking for. Happy New Year.

The popular All Bran muffin recipe uses oil. I make this recipe with olive oil. The muffins are light and moist. You can keep the batter in the fridge for up to two weeks and bake them fresh. I just read a tip to bake them in greased custard cups if you only want to bake one or two.

I add 1 tsp. cinnamon and orange zest for flavor.

https://www.kingarthurbaking.com/recipes/zella-lanes-2-week-bran-muffins-recipe 

well you cut down on the amount of fat, and cut back on the amount of raisins....that alone would have made enough to fill the 12th muffin cup. You subbed whole wheat pastry flour for AP flour, cutting back on the gluten needed for a rise, no wonder you thought they were dense....and you substituted a sweet apple for the tart....and thought they were too sweet.

You are not making a recipe you found but inventing someting different

Actually pastry flour makes much lighter muffins. Baked goods that aren't made with yeast as the rising agent, instead using baking powder or baking soda and an acid, do not need gluten for structure. From the article: "The low protein count creates a moist, fine crumb and fluffy texture in cakes and muffins." Now this is a bit of splitting hairs because the difference between pastry flour and AP flour is small, but it is noticeable and I love the texture and taste of whole wheat pastry flour. Since muffins are one of my favorite foods, I highly recommend using whole wheat pastry flour in them, particularly if like me, you are always looking to up the nutrition and fiber content of your foods. The lower protein helps counteract the heaviness sometimes associated with whole grains. Plus the taste is slightly different than whole wheat flour made from hard (higher protein bread flour) rather than soft wheat, like the pastry flour. Oh, and whatever you do, don't overmix your muffins, you actually don't want to build a gluten structure in something without yeast. And even in some light yeast breads, you want a flakier texture rather than a chewy one.

The Magical Thing Pastry Flour Does for Your Baked Goods

We've really been enjoying the muffins this week. Also made some pear ones that also called for just a little bit of oil, along with yogurt and baking soda as a boost to leavening. That recipe came from Cooking Light magazine.