Preheat oven to 350° F. Grease and line an 8X8-inch baking pan with parchment paper, set aside.
In a small bowl, whisk together the flour, salt, and baking powder.
In the bowl of an electric mixer, mix the butter and both sugars until well combined and fluffy. Add the egg and vanilla, mixing until combined.
Pour the dry ingredients into the wet, mixing until everything is incorporated. Fold in the chocolate chips.
Pour the batter into the prepared pan and evenly spread it out. Bake for 25-30 minutes, until golden brown and a toothpick inserted into the center, comes out clean. Allow the bars to cool completely before cutting into pieces.
Notes
STORE - Store in an air-tight container for up to one week.
FREEZE - Transfer cooled cookie bars {preferably pre-cut into squares} to an airtight container or freezer-safe zip-top bag. Line layers with wax or parchment paper, if needed. Freeze for up to 3 months.