Preheat the oven to 375 degrees F. Whisk the flour, baking soda and salt in a medium bowl. In a large bowl, beat the butter and brown sugar with a mixer on medium-high speed until pale and fluffy, 4 minutes. Beat in the egg and vanilla. Reduce the mixer speed to low and beat in the flour mixture until just combined. Stir in the chocolate chips.
Roll the dough into 1 1/2-inch balls; arrange 2 inches apart on parchment-lined baking sheets. Bake until set around the edges, 12 to 15 minutes. Let cool 10 minutes on the pans, then transfer to a rack.