The official Girl Scout website offers this "early Girl Scout Cookie Recipe."
(recipe taken from: http://www.girlscouts.org/program/gs_cookies/cookie_history/early_years.asp)
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AN EARLY GIRL SCOUT COOKIE® RECIPE
1 cup butter
1 cup sugar plus additional amount for topping (optional)
2 eggs
2 tablespoons milk
1 teaspoon vanilla
2 cups flour
1 teaspoon salt
2 teaspoons baking powder
Cream butter and the cup of sugar; add well-beaten eggs, then milk, vanilla, flour, salt, and baking powder. Refrigerate for at least 1 hour. Roll dough, cut into trefoil shapes, and sprinkle sugar on top, if desired. Bake in a quick oven (375°) for approximately 8 to 10 minutes or until the edges begin to brown. Makes six- to seven-dozen cookies.
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Two baking companies currently produce the cookies - ABC/Interbake Foods and Little Brownie Bakers. There are always Thin Mints, Do-si-dos (the peanut butter cookie formerly known as the Savannah) and Trefoils (the "original" Girl Scout cookie). Thin mints are the most popular, taking at least 40% of the sales. The other cookie types vary, depending on what is of interest at the time. Thin Mints are the third-most popular cookie in America.
Current prices range between $4.00 and $6.00 a box. All profits from cookie sales go directly to the council in which the cookies were sold. A portion go directly to the troop that was responsible for that sale.
In addition to serving as a fundraiser, Girl Scout cookie sales teach young girls about responsibility, pride, setting and meeting goals, money-management, and communication.
If you don't want the calories but still want to help out that little girl at your door, ask her about donating some cookies; if you buy and donate, your purchase becomes tax-deductible.
On the other hand, if you can't resist eating them yourselves but are watching your waist, the Trefoils generally have the lowest calorie count per cookie. The chocolate-covered shortbread varieties have the highest. The chocolate peanut-butter patties, big surprise, have the highest fat content, and the lemon cookies have the lowest. Who are we kidding though? Just order the Thin Mints like everyone else!