Use the paddle attachment of a stand-up mixer to cream the butter, brown sugar, and peanut butter. Cream thoroughly, at least two minutes on high speed.
Add the egg, and mix in slowly. Once it's mixed in, add the vanilla and maple syrup one at a time, allowing each to fully combine.
In a separate bowl, whisk the dry ingredients together. (Flour, baking soda, salt.) Slowly add them to your stand-up mixer on low speed, until they're completely mixed in.
Fold the chocolate chips in using a rubber spatula. Spoon out dough portions measuring 2 Tbsp. each, and form into balls. Place on a baking sheet lined with a silicone mat, and bake for 8-10 minutes at 350.
Remove the cookies from the oven, and let them cool on the baking sheet for about ten minutes. They'll continue baking a little as they sit on the baking sheet. Transfer to a wire rack when they're done.
Serve warm, or store in an airtight container for up to a week.
Notes
Optional : drizzle with chocolate sauce (melted chocolate chips with a dash of heavy cream), and with flaked sea salt.