According to Shirley Corriher in "CookWise," the type of fat and flour you use in a cookie will change the type of cookie you get. For thin chocolate chip cookies, use butter and bleached all-purpose flour. For puffed cookies use shortening and cake flour. Here are recipes for both types of cookies, from "CookWise."

For the thin cookies, butter helps them spread as they melt, as does more liquid in the dough. Corn syrup promotes crispness and color; baking soda also enhances color. Bleached all-purpose flour does not absorb a lot of liquid.

For the puffed cookies, shortening and cake flour limit spread, as does baking powder. Cutting fat and sugar a little helps to limit spreading and egg helps the cookie puff.

Both recipes share the same directions.

THIN CHOCOLATE CHIP COOKIES

1 cup coarsely chopped pecans or walnuts
2 tablespoons butter
1-1/2 cups bleached all-purpose flour
3/4 teaspoon salt
3/4 teaspoon baking soda
10 tablespoons butter
1/2 cup sugar
1/3 cup light brown sugar
3 tablespoons light corn syrup
2 tablespoons milk
1 tablespoon pure vanilla extract
1 cup (6 ounces) semisweet chocolate chips

PUFFED CHOCOLATE CHIP COOKIES

1 cup coarsely chopped pecans or walnuts
2 tablespoons butter
1-1/2 cups cake flour
3/4 teaspoon salt
1-1/2 teaspoons baking powder
9 tablespoons butter flavored shortening
1 cup minus 1 tablespoon brown sugar
1 large egg
1 tablespoon pure vanilla extract
1 cup (6 ounces) semisweet chocolate chips

Preheat oven to 350 degrees. On large baking sheet, roast pecans or walnuts 10 to 12 minutes. Remove from oven and, while nuts are still hot, stir in 2 tablespoons butter.

Turn up oven heat to 375 degrees.

Sift together flour, salt and baking soda or baking powder in medium mixing bowl.

Using electric mixer, cream fat and sugar in large bowl until light and fluffy. Add corn syrup if using, Add liquid or egg and beat thoroughly. Beat in vanilla.

On low speed, gradually add dry ingredients until thoroughly combined. Scrape down sides once. Add pecans and chocolate chips. Beat 5 seconds on low. Use rubber spatula to finishing mixing in well.

Spray cookie sheets lightly with nonstick cooking spray. Drop slightly heaped tablespoons of batter about 2 inches apart onto greased sheets.

Bake cookies about 12 minutes or until edges just begin to brown. Remove from oven and let cool on sheet on cooling rack for 3 minutes, then remove cookies to rack to cool completely. Makes 24 cookies

Approximate nutritional information, per thin cookie: 180 calories, 11 g fat, 5 g saturated fat, 15 mg cholesterol, 150 mg sodium, 20 g carbohydrate, 1 g fiber, 13 g sugar, 2 g protein

Approximate nutritional information, per puffed cookie: 180 calories, 11 g fat, 3.5 g saturated fat, 10 mg cholesterol, 100 mg sodium, 20 g carbohydrate, 1 g fiber, 14 g sugar, 2 g protein