Beat together butter and both sugars in a large bowl with an electric mixer at high speed for 2-3 minutes. The mixture will become pale and a bit lighter.
Add egg to butter mixture, beating with mixer until creamy, about 1 minute. Beat in vanilla, baking soda and salt.By hand, stir in flour until just blended; stir in chocolate chips.Using a VERY generously heaping tablespoon measure, scoop up 14 mounds of dough and arrange on a foil lined plate. Chill until firm (recommended) or bake immediately.Preheat oven to 350 degrees F or for crisper edges and softer centers, 375F. Have ready two ungreased or foil lined cookie sheets. You can line them with parchment if you want, but they the cookies will spread less if you use regular foil or just leave the cookie sheets ungreased.Arrange dough mounds about 2 ½ inches apart on cookie sheets (7 to a sheet).Press down centers just slightly.
Bake 1 sheet at a time on center rack for about 12-15 minutes or until edges are browned.
Let cookies cool on cookie sheet for about 3 minutes, then transfer cookies to a rack to cool completely.
