Perfectly Chocolate Chocolate-Chip Cookies

2 1/4 c flour
1/3 c cocoa
1 tsp baking soda
1/2 tsp salt
1 c (2 sticks) butter, softened
3/4 c granulated sugar
3/4 c packed light brown sugar
1 tsp vanilla extract
2 eggs
2 c (12 oz pkg) choc. chips
1 c nuts (optional)

Heat oven to 375 deg.
Stir together flour, cocoa, baking soda and salt.
In a separate large bowl, beat butter, sugar, brown sugar and vanilla on medium speed until creamy. Add eggs. Beat well. Gradually add flour mixture, beating well. Stir in choc. chips and nuts, if using. Drop by rounded teaspoons onto ungreased cookie sheet. Bake 8-10 min. or until set. Cool slightly, remove from cookie sheet to wire rack. Makes about 5 dozen cookies.