If you want to use oil in a cookie recipe, it's best to find recipes that already has it as an ingredient rather than substituting it for a solid fat. You will get different characteristics if you use oil as a substitute. According to Betty Crocker's Cookie Book: -Vegetable oil cannot be substituted for a solid fat. Most recipes using oil call for half oil and half butter, margarine or shortening. -Cookies made with part vegetable oil and part butter, margarine or shortening... *Have no buttery taste *Are flatter, chewier and crisper *Have crackly or crinkled tops -Cookies made with ALL vegetable oil... *Are crisp if recipes calls for no added liquids such as milk, juice or water *Are soft and moist if liquids such as milk, juice or water are added to the recipe *Are crispy cookies with crackly or crinkled tops -Grainlady

From Baking 911 Each type of fat used in cookie recipes separately affects the cookie's texture and taste. Generally, the use of butter means a flatter, crispier cookies because it allows the dough to spread as it cooks on the hot cookie sheet. Cookies made with shortening will not spread, however all shortening will give you a cookie without a lot of taste. This approach gives you the best of both worlds: shortening is not as sensitive to shifts in temperature and the butter gives a lot of flavor. Shortening: Least spread / Least flavor, however can use butter flavored. Because of its higher melting point (98 to 100 degrees F) than butter, cookies keep their shape as it bakes, yielding a puffier more cake-like treat. Stick Butter: Medium spread / Best flavor. Because of the lower the melting point of butter (92 to 98 degrees F) than shortening, cookies spread and become flatter and crispier as the result. To help reduce cookie spread when using butter, freeze the formed dough on the cookie sheets. When you place the frozen cookie dough immediately in the oven, the fat will stay colder longer and when baked, the cookie will retain its shape better. For flavor, there is no substitute for butter. Cookies made with butter have outstanding taste and a finely grained, often crisp texture. Butter also helps cookies to keep well and maintain their flavor. I recommend using unsalted butter in baking. Stick Margarine: Most spread / Some flavor Vegetable oils: cookies are softer than those made with butter or margarine.

Hi OJ. Here's my recipe that I've had for years. I just got Brigette, and I've made these cookies years ago with a hand mixer. Peanut Butter Cookies 1/2 cup butter 1/2 cup brown sugar 1/2 cup white sugar 1 egg 1/2 cup peanut butter 1/2 tsp salt 1/2 tsp baking soda 1 cup flour 1/2 tsp vanilla Cream butter; add brown and white sugar gradually, beating until creamy. Mix in egg, peanut butter, salt and baking soda. Blend in flour slowly. Add vanilla and mix well. Roll into small balls or drop by teaspoonfuls and place on parchment lined cookie sheet. Press with floured fork. Bake at 350 degrees 10-12 minutes.

Maybe reading this article will shine some light on the subject: http://sweets.seriouseats.com/2013/12/the-food-lab-the-best-chocolate-chip-cookies.html I know it's about chocolate chip cookies, but the science may help you out. Thanks for sharing the oatmeal - fat absorption - factoid. I find that really interesting and will add it to my "Book of Odd Knowledge" for future reference. I don't think it's just better mixing (you always want to keep mixing to a minimum for cookie dough so you don't over-develop the gluten and get tough cookies), but I think it's all about using a liquid fat and refrigerating the cookie dough for 12-24 hours so the flour has time to absorb the moisture, and therefore the cannabutter as well. Recipes for cookies using a liquid fat are less common, but once you have a few for comparison, you should be able to come up with a cookie (with the ingredients you posted in your second request for a recipe with specific ingredients). Just keep an eye out for the ratio of ingredients as your clues to how much liquid fat to flour. Since cannabutter is made by melting the butter, that's another reason to stick to a recipe using a liquid fat. Once butter is melted and resolidified, it doesn't work the same in a recipe. Other recipes you might want to research are those that use ghee, which initially is made with melted butter, as well. Editing to add: liquid fat is absorbed by flour while solid fat coats flour. Be sure to let us know how things work. -Grainlady