How to create a muffin recipe

Michael Ruhlman's Ratio defines a muffin as a form of a quick bread. The basic quick bread ratio is:

• 2 parts flour
• 2 parts liquid
• 1 part egg
• 1 part fat

So you can make a muffin with those basic ingredients in about that ratio. Remove any of those ingredients, and you no longer have a muffin. Substantially change those ingredients, and you've moved somewhere else in the dough continuum or even towards a batter.

Personally I'd classify a cupcake as a type of cake. The ratio for pound and sponge cake are both:

• 1 part butter
• 1 part sugar
• 1 part egg
• 1 part flour

The differences between cakes are often the mixing method - creaming versus foaming, for example. You can see, though, that in a muffin your flour-to-fat ratio is higher than in a cake. Muffins also don't require sugars. Cakes and cupcakes do.

From the basic quick bread ratio, you should be able to add any fruit or other ingredients (try bacon or turkey bacon), substitute in dry ingredients for flour such as bran or oatmeal (or another grain), and make a lot of other interesting changes. Just make sure you stick to the basic proportion of a quick bread. If you add a very wet ingredient, remove some liquid. Change tastes by adjusting oil versus butter (or browning your butter). Add sugar, baking powder or soda for leavening, spices, extracts, etc.

Whew. This isn't as easy as you'd think. The short of the "cupcake" question is simple though: often there is no difference. Many big breakfast chains will serve you cake batter "muffins" in a heartbeat. A true muffin will be a bit coarser, a bit more bread-y. It's like the difference between a biscuit and a scone.

The basic muffin (oil,egg,milk,powder,flour) is easy. The problem is when you start mixing in flavor. For heavy stuff (pumpkin leaps to mind) you need to add more baking powder and baking soda as well. I also tend to separate my eggs, and fold in some beaten egg whites for a little extra lightness.

For berries and wet things, shake 'em in some flour first, so all the fruit doesn't settle to the bottom of the muffin. I'd shake them in the flour you plan on using for the muffins, so you don't get too much flour in your batter. If you're using frozen fruit, don't bother to thaw.

Sour cream, yoghurt, and buttermilk can all be subbed in for some of the milk. Thicker batter needs to have proportionately more leavening agent, while looser, wetter batter should have less (so as to avoid weird bubbles). There is no "right" consistency for muffin batter: some will be thicker and some will be thinner.

With subbing in different fruits and vegetables, the most important thing to consider is their water content. Berries are pretty much interchangeable. Apples and peaches, on the other hand, aren't. I'd rate a peach as being more like a berry in that sense (I used to go to a place that made peach and cream cheese muffins that were literally worth killing for. Literally.)

I'm basing this off of observing these recipes all from Smitten Kitchen. I'm using all the same site with the thought that I want the same person making (or at least adapting) all the recipes.

• http://smittenkitchen.com/2007/05/always-the-corniest/
• http://smittenkitchen.com/2008/11/olive-oil-muffins/
• http://smittenkitchen.com/2006/10/promise-keeper-pumpkin-eater/
• http://smittenkitchen.com/2007/05/a-new-muffin-in-town/
• http://smittenkitchen.com/2010/01/ricotta-muffins/
• http://smittenkitchen.com/2007/02/a-meatover-and-a-muffin/
• http://smittenkitchen.com/2008/04/whole-wheat-apple-muffins/

Here's a quick approximation of wet to dry for each (not including small amounts of leavening or spices or things like apples that are both wet/dry ingredients):

• corn: 2.25 C. dry to 1.5 C. wet
• olive oil: 2.75 C. dry to 1.5 C. wet
• pumpkin: 2.75 C. dry to 1.5 C. wet
• raspberry: 3.15 C. dry to 1.7 C. wet
• ricotta: 3.75 C. dry to 2.5 C. wet
• sour cream: 2.25 C. dry to 1.75 C. wet
• wheat: 3 C. dry to 1.75 C. wet

As you can see, most recipes have about 3 cups of dry ingredients to 1.5 or 2 cups of wet ingredients. To be more detailed:

• Most of the recipes have about 1 C. flour and 1 C. sugar.
• Around 1/2 C. of fat (butter or oil).
• Between 0-2 large eggs...so I would try 1 egg to start with.
• Between 1/2 tsp. and 1 Tbsp. baking soda...so I would try 2 tsp.
• 1/2 tsp. of salt.

As to your other questions, I think the other respondents nailed them:

• Cupcakes have frosting, muffins might have a light icing at most.
• Adjusting for berries, other fruits and so on depends a lot on the season.

The biggest differences between muffin and cupcake:

(1) muffins are usually not frosted, at most lightly glazed (2) muffins usually just have you mix wet and dry ingredients separately, while cupcakes have you cream the butter and sugar

When substituting fruits and veggies, you don't need to worry much. Start by doing it simply by volume (1 cup of berrries instead of 1 cup of apple pieces) and you won't be too far off. If the new ingredient is significantly wetter or drier you might want to adjust the liquid a bit.