The ones in most bake shops aren't really true muffins, but rather a type of cake. Muffins are basically a quick bread baked in a muffin tin. If you've been trying recipes and they're not rising to the occasion then it might be your leavening. Make sure you have fresh Baking Powder and then shake it up before every use - the contents settle in layers.

You may be over-mixing the batter. Muffins like to be mixed just enough to have all the ingredients incorporated.

perhaps try finding a recipe for French breakfast puffs.

CA Kate, Thanks for the tip about shaking the baking powder -- never heard of that! I guess what I am craving is cake, not muffins! Oh, dear...

party_music, I do try to not over-mix, but may be failing in that. Will be more careful!

sonni1, thanks -- off to search for those, thanks!

Roxanna, try looking at this link from King Arthur for muffins. It can be a good source, but there are many others.

https://search.kingarthurflour.com/search?w=muffins&deftab=recipes 

Test your baking powder; put a pinch on your tongue, or add a drop of water. It should foam up. If it doesn't, time to buy fresh. First I ever heard of fluffing it.

High humidity can make baking powder lose its effectiveness. I store my can of baking powder in a tightly closed glass jar with a few silicon moisture absorbing packets.

And a typical quick bread recipe calls for 1 tablespoon (3 teaspoons) of baking powder. Can you share the recipe you're using?

And yes, batter should be lumpy and undermixed-looking

Pastry flour or cake flour, can make lighter muffins. Makes a big difference.

As Carol posted, test your baking powder by putting a little in warm water. For baking soda, use vinegar.

My advice is exactly what plllog posted. And look for recipes that use both double acting baking powder and baking soda.

Any bakery will do what sells. A more cupcake like muffin that has a rise just has more loft (air). Cost is the same as a traditional more dense smaller muffin.

Not sure what your favorite bakery muffin is but I've been making a very old recipe that is a southern corn muffin. No sugar. I use it as my base mix and after 5-7 minutes I add any number of 'top-dressings' on hand from savory to slightly sweet (for my dad). : )

That reminds me. When I was a kid, muffins were down homey, and not often found in city bakeries. And they were the size of the cups on the muffin tin, without overflowy tops. We had to make them for school, however, as well as making them at the ranch. There were muffiny muffins, like bran, oatmeal, and date/nut. They were very moist and fairly dense. OTOH, fruit muffins, like blueberry or lemon, were much lighter and cakier, and poppyseed was somewhere in between. Which is totally explainable by the weight of the ingredients, as well as how much moisture they suck up. :)

I do a blueberry/bran muffin with zucchini added and made with applesauce instead of oil if you're interested. I'm sure you could delete the blueberries.

nancyjane, would love for you to post that muffin recipe!

I made some overly dense muffins recently and did some research, and found out that too much baking powder can also be a problem, the muffins can rise and then collapse on themselves. The ratio should be no more than 1 tsp. baking powder per 1 cup of flour. Also, if you are adding a fruit to it, toss them in flour to coat first so they don't spread too much liquid throughout your muffin making it gooey.