Inventing Cookie Recipes

Use zest instead of juice for flavour.

I'd start with a basic recipe and gradually tweak it to suit. Depends whether you want something that's chewy, or short or crisp, or whether you want a biscuit dough that wants rolling before using cutters or a looser dough that you simply dollop onto the baking sheet. Most recipes I know don't have a great deal of liquid in them - usually the butter and an egg is enough to bind the mixture together.

I second the use of lots of zest, but too much might make the end result bitter. You might want to look at using essences or extracts to give you the intensity of flavour while still retaining the kind of texture you want...

Here's a recipe for a basic lemon biscuit that wants rolling out and cutting.

8oz plain flour

1/2 level teaspoon salt

4 oz butter or marg

4 oz caster sugar

2 level teaspoons lemon zest

1 teaspoon vanilla extract (you could swap this for lemon extract if you want that intense flavour)

3 to 4 tablespoons beaten egg

Sift flour & salt into a bowl. Rub in the fat until the mixture resembles breadcrumbs. Add the sugar. Mix to a stiff paste. Knead lightly until smooth. Wrap in cling film and refrigerate for 30 mins. Roll out thinly on a floured surface and cut into rounds etc, re-rolling and cutting out trimmings. You should get about 24 from one batch. Bake for 12 to 15 mins in preheated oven 350F / 180C / Gas 4 until light gold in colour.

HTH ;-) 

take the time to analyze a number of familiar recipes.  Best done if you convert the ingredient quantities to weights, of course.  That will let you see how various ratios affect the physical traits of the different cookies.  Note baking times and temps, too, since that also has a big influence on the finished cookie. 

That knowledge will give you a starting point for making a new cookie. 

Paul

Look for True Lime crystallized lime powder, probably with the bottled lemon/lime juice at your grocery store. They make a lemon version too. 1 Tbl = 1/2 cup lime juice. Beware that that much acidity will change the browning characteristics of your cookie, and you may need to turn up the oven temperature to compensate. You could also mix some of the powder with sugar to roll your cookies in before or after baking. Best of luck with your project

I've been messing with cookie recipes for 40 years (my first baking love and still my favorite thing to make), and I can now get something close to what I want the first time maybe 2/3 of the time, and something worth tweaking further most of the rest of the time.  It's tricky to get it perfect in one go--I especially cherish the Pfefferneuse I created based on polling family members about a recipe one of my sisters clipped from a newspaper but that was long lost, because it worked the first time.

Keys to success for me are starting with recipes I know well and like (the ones that were family favorites growing up, and that I basically have memorized), and rewriting them as lists of ingredients, grouping the fats/oils, liquids, sugars, flours, leavenings and mostly texture-neutral additives like dried fruits/chopped nuts/spices together. 

Here are a couple of examples of how I do this, more formal than the usual back-of-the-envelope notes, one for Toll House Cookies and one for Shortbread cookies.

Then I think about what I want to adjust:  make it more buttery?  Change white sugar to brown sugar and molasses for more intense flavor?  Substitute some part of the flour with oatmeal or ground nuts for texture and flavor?  And I make as sure as I can that those changes are balanced within that subset of ingredients.  I rarely mess with the leavenings (baking soda/baking powder/cream of tartar) or salt. 

I have at this point a repetoire of a dozen or so master recipes that are my usual jumping off points, like Grandma's icebox cookies, my own Poppyseed shortbreads, or the Oatmeal-Raisin cookies from the 1950s Betty Crocker cookbook.

For example, if I want to cut down on the sugar, which acts both as a liquid during baking (it melts), and as an agent for crispness in the baked cookie, I might add some milk or egg to compensate for the decrease in liquid, and if the cookie is meant to be crisp, substitute 10-15% of the wheat flour with rice flour.  If I want to add 1 cup of ground nuts or oatmeal, I drop the flour by about half that amount, 1/2 cup or about 75 grams.  If a recipe calls for shortening and I'm substituting butter, I try to remember that standard US butter has enough water content to make touchy cookies soft and spreading, and either decrease it a bit, up the flour a little, or drop the egg or other liquid flavoring to compensate.  Adding a teaspoon or two of liquid flavoring (extracts & oils) is generally trivial, but adding juice enough to flavor a recipe takes major tweaks. 

I try to work by weight at least for the dry/flour ingredients, which happens by necessity because I'm nearly always converting all-purpose flour to fresh milled whole grain flour based on weight. I know this isn't the milling subforum, but I put together some examples of how I do this conversion on this page about baking with whole grains.

Does that help?