Line two baking sheet pans with parchment paper. Preheat conventional oven to 350 degrees F. If using raisins, measure, chop and moisten raisins, draining well. Set aside.
In large mixing bowl, beat margarine and sugars until creamy. Add egg, ground flax meal and water and beat until fluffy. Add vanilla and salt.
In separate bowl, whisk to blend well the flour, baking soda, baking powder and cinnamon (if using.) Add the rolled oats and stir well.
Add dry mixture, mix briefly; add milk and raisins (if using) mixing just to blend.
Drop by teaspoonfuls or small cookie scoop onto parchment-lined cookie sheets, spacing about 1 or 1 ½ -inches apart. Bake on center oven rack, 10-12 minutes, conventional oven.
Remove sheet pan from oven and cool briefly on wire cooling racks. Remove cookies to rack to completely cool. Store in sealed containers or food storage bags. Freeze for best quality unless serving within 24 hours.
Yields 2-3 dozen regular oatmeal cookies or 3 dozen oatmeal raisin cookies.
Original recipe by Clabber Girl. Revised by HomeBaking.org and Sharon Davis, FCS Education.