Supposedly an acronym (Chocolatechip Oatmeal Walnut) but really they do look just like COW Cookies
(makes 22 4-inch cookies)

2 cups flour
1 teaspoon salt
1 teaspoon baking soda
1 teaspoon baking powder
1 cup (2 sticks) butter, room temperature[OK, the original recipe calls for margerine, but... yuck.]
1 cup firmly packed brown sugar
1 cup sugar
2 eggs, room, temperature
2 tablespoons milk
2 teaspoons vanilla
2-1/2 cups rolled oats
1 12-ounce package semisweet chocolate chips[I often substitute chopped dates for part of the chocolate chips.]
1-1/2 cups chopped walnuts[I use any nuts I happen to have.]

Position rack in center of oven and preheat to 350 degrees. Grease baking sheets. Dust with flour.[I don't.] Combine flour, salt, baking soda, baking powder. Cream butter with both sugars until fluffy. Add eggs 1 at a time, beating until fluffy. Mix in milk and vanilla. Stir flour mixture into batter. Fold in oats, chips, and nuts.
Using 1/3 cup for each cookie, drop batter onto sheets[I dip the 1/3-cup scoop into water between fills; allow four cookies to a standard-size cookie sheet.], spacing 3 inches apart. Bake until light brown at the edges, 12 to 15 minutes. Cool on sheets 3 minutes, then transfer to rack and cool completely.

Sam Mills: RECIPES