Preheat oven to 350 degrees. Line baking sheet with parchment paper or silicone baking mat and set aside.
In large bowl, cream butter and sugar. Stir in egg and vanilla. Scrape sides and whip until light and fluffy. Stir in all dry ingredients until just incorporated. Scrape sides and mix again briefly. Stir both kinds of chocolate chips into dough.
Scoop onto prepared baking sheets and bake 8-9 minutes. Cool cookies 5-10 minutes on hot baking sheet to finish baking, then remove to cool completely. Store in an airtight container for up to 3 days.