Heat oven to 375°F.
Beat butter, granulated sugar, brown sugar, vanilla and salt in large bowl until creamy. Add eggs; beat well.
Stir together flour, cocoa and baking soda; gradually add to butter mixture, beating until well blended. Drop by rounded teaspoons onto ungreased cookie sheet.
Bake 8 to 10 minutes or until set. Cool slightly; remove from cookie sheet to wire rack. Cool completely.
Chocolate Chocolate Chip Cookies: Add 2 cups (12-oz pkg.) HERSHEY'S SPECIAL DARK Chocolate Chips, Semi-Sweet Chocolate Chips, Mini Chips Semi-Sweet Chocolate OR 2 cups (11.5-oz pkg.) HERSHEY'S Milk Chocolate Chips to basic chocolate batter.
Mini KISSES Chocolate Cookies: 1-1/2 cups (9-oz pkg.) HERSHEY’S MINI KISSES Chips
Chocolate Cookies With White Creme Chips: Add 2 cups (12-oz pkg.) HERSHEY'S Premier White Creme Chips to basic chocolate batter.
Chocolate Cookies With Peanut Butter Chips: Add 1-2/3 cups (10-oz pkg.) REESE'S Peanut Butter Chips to basic chocolate batter.
Chocolate Cookies With Toffee: Add 1 to 1-1/4 cups HEATH BITS O' BRICKLE Toffee Bits or HEATH Milk Chocolate Toffee Bits to basic chocolate batter. Lightly grease or paper-line cookie sheets.