It's caused by over mixing the batter...The problem is commonly called "peaks and tunnels"...because it's often accompanied by holes on the inside.
Linda C

I didn't know that Linda.
I always thought that it was caused by letting the bread/muffin mixture sit out too long before putting in the oven. The leavening agent would start to work.
Always learning something new here.
Looking forward to the Lemon Bread recipe.

Di

Thanks Linda! I didn't know. I love muffins though! I do have a couple of yummy muffin recipes.

Basic Muffins

This recipe is from the Farm Journal's Homemade Breads by Alice Joy Miller, Joanne G. Fullan and Margaret C. Quinn. It makes 12 muffins (regular size).

Ingredients

2 cups flour
1/3 cup sugar
1 tablespoon baking powder
1/2 teaspoon salt
1 cup milk
1/3 cup vegetable oil
1 egg

In a large bowl, mix flour, sugar, baking powder, and salt, set aside.

In a small bowl, mix milk, oil, and egg until well blended. Add milk mixture to dry ingredients; stir until moistened. Spoon batter into 12 paper lined or well greased muffin tins. Bake at 400 degrees F for 25 minutes. Let cool 5-10 minutes and remove from pan.

Pat's Blueberry Muffins

This recipe is from Taste of Home 1999 Annual Recipes, editor Julie Schnittka. It makes 12 regular size muffins.

Ingredients

2 cups flour
1/3 cup plus 2 tablespoons sugar
1 teaspoon salt
1 tablespoon baking powder
1/4 cup butter or margarine, melted
1 egg
1 cup milk
1 cup fresh or frozen (but thawed) blueberries

In a large bowl, mix flour, sugar, baking powder, and salt. Add blueberries. In another bowl, beat egg and milk, stir in butter. Mix wet ingredients into dry ingredients until just moistened. Spoon batter into paper lined or well greased muffin tins. Bake at 400 degrees F for 25 minutes. Let cool 5-10 minutes and remove from pan.

Jalapeno Corn Muffins or Bread

This comes from Taste of Home 2000 Annual recipes, editor Kathy Pohl. This makes 9-12 muffins or a 9x9 inch baking pan.

Ingredients

1 cup cornmeal
1/2 cup shredded cheddar cheese
2 teaspoons baking powder
3/4 teaspoon salt
2 eggs, beaten
1 can (8 3/4 oz) cream style corn
1 cup buttermilk
1/4 cup vegetable oil
1 to 2 tablespoons minced fresh jalapeno peppers

In a large bowl combine cornmeal, cheddar cheese, baking powder and salt. Combine the remaining ingredients into another bowl. Mix the wet ingredients into the cornmeal mixture until just moistened. Spoon batter into paper lined or well greased muffin tins or a greased 9x9 inch pan. Bake at 350 degrees F for 45 minutes for muffins or 1 hour for pan. Let cool 5-10 minutes and remove from pan.

Editor's Note: you may want to wear gloves when cutting and seeding hot peppers.

No holes. Just the "peak." Hmmm...I shouldn't think I'd been overmixing, 'cause my Mom was death on that. I'll try to be still gentler about it and see what happens.

The rest of the story....

When it comes to all quick breads (loaves, biscuits, scones, soda breads, muffins, pancakes, and popovers), it's all about keeping gluten-development in the flour to a bare minimum. That not only includes mixing methods, tools used in mixing, but also the kind of flour you use.

Start by using a flour that is lower in gluten (protein) to begin with. All-purpose flour is typically called for in recipes, but not all all-purpose flours are equal in the gluten division.

--King Arthur Unbleached All-Purpose, Robin Hood and Hecker's are considered Northern all-purpose flours with the highest amount of protein (11-12 percent). Personally, I'd avoid these for most quick breads. If you do use them for quick breads, make sure you keep mixing to a bare minimum. You can also add a little more fat to off-set the gluten development, or choose a muffin recipe with more sugar in it. Sugar is a good tenderizer.

--National Brands (Gold Medal, Pillsbury) - 9.5 to 12 percent.

--Southern Brands (White Lily, Martha, Gladiola, Red Band) - 7.5 to 9.5 percent, and is a better choice for pie crusts, biscuits, quick breads and muffins - those baked goods where you don't want a lot of gluten development.

Mixing methods and their results:

Traditional Method: All the steps are geared to minimize mixing. The fat is usually in a liquid form (vegetable oil or solid fats like butter or shortening that have been melted). The eggs and other liquids are mixed together in one bowl while the dry ingredients are mixed in another bowl. Then the liquid ingredients are added all at once to the dry ingredients.

Cake Method: The solid fat and sugar are creamed together. This method is used when there is a high ratio of fat and sugar. The resulting muffins will be very tender, and are also more cake-like.

Muffin recipes with a high fat content not only taste rich, but they have a soft crumb and will tend to be better keepers.

Avoid too much gluten development by mixing quick breads by hand, rather than using an electric mixer. One of the best tools for mixing batters is a Danish Dough Whisk (see link below). The batter SHOULD be lumpy, rather than smooth. There may even be small bits of dry flour remaining in the batter, but it will disappear as the batter bakes. If you have beaten the batter until it is smooth, you have over-mixed it.

The longer you stir by hand, or mix the batter with an electric mixer, the stringier the batter becomes. This means the gluten in the flour has been over-developed and the gluten will be in long, tough, strands. When you open the muffins, you'll find tunnels inside, and a compact texture. The tunnels develop when the leavening gases have to work really hard to "drill" their way through the long gluten strands in the tough batter. These narrow holes will run from the bottom to the top of the muffin, and are hallmarks of over-mixing.

The "Blue-Ribbon" winning muffin is symmetrical with a slightly rounded top. The surface is pebbly or bumpy. The volume of a freshly-baked muffin is about double the size as the amount of batter used. It should feel light in proportion to its size. A good muffin is tender and breaks apart easily. The crumb should be moist inside, the texture even. NO tunnels!

An over-mixed muffin will have a pale, slick, peaked top.

-Grainlady

Here is a link that might be useful: King Arthur Flour - Dough Whisk

One fix is to hollow out a slight trough with your mixing spoon down the middle of the loaf after you have spooned the batter into the pan. My pumpkin apple bread recipe has you do this before putting the strusel topping on the loaf.

Teresa

Well, I made some corn bread last night. 24 gem muffins and one mini-loaf. Kept mixing to an absolute minimum, there were plenty of lumps (like Mom always told me to leave alone) and the results were very tasty. Like I said before, good flavor and crumb, no tunnels. But still, I got the Sombrero look. Not as much as I have gotten with straight muffin recipes but there. The loaf had more of it than the gem muffins.

The flour info is interesting. I knew different flours had different gluten levels (never could make a decent wheat loaf until I heard about adding a wee bit of gluten flour) but as I use the same flour from batch to batch, that in and of itself doesn't explain why this only happens sometimes!

A couple of weeks ago, I made a pan of cornbread that looked beautiful...modestly and evenly domed.

Sigh.

Okay, promised Lemon Bread Recipe:

Lemon Bread

1 c oil
2 c sugar
4 eggs
3 c flour
1/2 t baking soda
1/2 t salt
1 c buttermilk
1 c chopped walnuts (see my notes)
2 T grated lemon peel
Topping:
1 c sugar
1/2 c lemon juice

Cream oil and sugar together; add eggs, slightly beaten. Mix together flour, baking soda and salt. Beat into mixture, alternately with buttermilk, until smooth. Stir in chopped nuts and lemon peel. Spoon into greased 9"x5" pans. Bake for 1 hour in a 350 F preheated oven. Cool Slightly. Remove from pans. Heat topping ingredients until sugar is melted. Place loaves on pieces of foil. Pour topping over bread. Cool, wrap and store in refrigerator or freezer. Makes 2 loaves.

The above is the recipe as it appears in, "The Tastes Of California Wine Country Napa/Sonoma, written and compiled by Sonnie Imes. It is a cookbook I've had for years, featuring recipes from various Bed & Breakfasts in that area. The Lemon Bread recipe comes from a place called, "Healdsburg Inn on the Plaza" which, to my knowledge still exists, though whether they still serve this bread is anyone's guess.

My Notes: This bread is fine made with your basic lemon. But I far prefer Meyer Lemons for their rich flavor. I do not add walnuts for two reasons,for one thing, I've never cared for nuts in quick breads. They lose any crispness, becoming mere chewy lumps as far as I'm concerned. For the second thing, walnuts give me mini blisters on my tongue. I sometimes do add dried cranberries, plumped slightly in some sort of fruit liqueur. Most often, I just let the lemon flavor stand alone. One can always serve the bread with a fruit puree on the side or a good, home made jam.

The recipe calls for you to "pour topping over bread." I have found that direction to be inadequate. Place the loaf in a large baking dish or serving dish, something that has sides to catch the liquid topping and large enough for room to spoon it up as it pools so you can drizzle it back onto the loaf. The loaves should absorb every bit of the topping. Turn the loaves on their sides to soak up pooled topping as well. The top and sides of the loaf should be well inundated.

Just before serving, I sprinkle the loaves with lemon flavored powdered sugar. I make this by whirring sugar, more lemon peel (I grate extra when I make the loaves and leave it out to dry a bit while they bake) and a few drops of lemon extract in a spice grinder. Plain powdered sugar would do, of course. This must be done just before serving because the sticky topping will soak into the sugar if given time to do so, leaving it icky looking.

This is wonderful served as a "strawberry shortcake" in lieu of the shortcake.

Thanks for the lessons. I mix to death!

I do have the dough whisk so I am eager to put the lessons in practice.

Here's another source for the Danish dough whisks that's lots less expensive than KA.

This is where I ordered mine. I bought the larger one and really wish that I had the smaller one. The big one is just too large for single batches of muffins and one-loaf recipes, IMO. From this source, you can get both sizes for the price of just the larger whisk from KA.

IIRC, Breadtopia ships from Iowa. No problems w/ the order & I rec'd my order in very good time but I'm in WI so it's just a shop hop from Iowa. Also, don't remember the shipping costs but do recall that they seemed reasonable.

Here is a link that might be useful: Breadtopia Dough Whisks

Those are a good price on a dough whisk if that is all you are ordering.

I recently bought two dough whisks and "Artesan Bread in 5 Minutes a day on Amazon. It came to under $30 with shipping.

ATK's in one of their publications addressed this very problem. In fact, they showed the difference between a peaked cupcake vs. a flat or slightly domed one, showing which (of course) was easier to add frosting to.

(I hope I'm remembering this right.)

I recall being particularly interested in the article because I've had this happen before...but then, who hasn't?

IF I'm remembering correctly, I thought they said the problem was baking at too high a heat, claiming a more moderate oven would keep the tops from ''peaking''. Of course I can't find the article now to back up what I'm saying, but I thought they said 350 degrees was the best temperature for baking for that reason. (Duh.) It may be your oven temperature is not accurate or needs to be calibrated, so double check the temperature with an oven thermometer to see if this might be the culprit.