Cream shortening and sugars in large bowl. Stir in Egg Replacer mixture and vanilla. Stir in flours, baking soda, and xanthan gum. Mix well.
Stir in oats. You want the mixture to be neither too sticky to work with, nor too dry. Stir in extras of your choice.
Drop by teaspoonfuls, flattening slightly, on an ungreased cookie sheet.
Bake at 375 °F for 12-14 minutes. Let cool for a minute on the cookie sheet, and slide onto a cooling rack.
Add ins: chocolate chips, or raisins or other dried fruit
If you can use eggs, replace egg replacer mixture with 2 whole eggs.
Corn Substitutions: Corn is a common ingredient in products. Starch, modified food starch, dextrin and maltodextrin can be from corn. Consult with your physician to find out which corn derivatives you need to avoid. Many corn-free options are available in the US. Find out more about corn substitutions.
Egg Substitutions: There are many egg-free products and foods available to make your recipes free of eggs. Find out more about egg substitutions.
Gluten: Gluten is a protein found in specific grains (wheat, spelt, kamut, barley, rye). Other grains are naturally gluten-free but may have cross-contact with gluten-containing grains. Look for certified gluten-free products if you need to avoid gluten. Find out more about wheat and gluten substitutions.