Preheat oven to 375°F. Line a baking sheet with parchment paper.
In a large bowl, cream together the butter and sugars until light and fluffy. Beat in the egg and vanilla.
In a separate bowl, whisk together the flour, baking soda and salt. Gradually add to the creamed mixture until just combined.
Stir in the chocolate chips or chunks.
Roll dough into 1-inch balls. Flatten slightly and place on prepared baking sheet. Place a small ball of cookie dough in the center of each cookie and press down slightly.
Bake for 8-10 minutes or until golden brown. Allow to cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely.