Preheat oven to 350°F.
In a large bowl, cream butter and sugars. Add eggs and vanilla; mix well.
In a separate bowl, combine flour, baking powder, cinnamon, pepper, salt, xanthan gum, and expresso powder; add to butter mixture and mix well.
Stir in chips.
Place rounded tablespoonfuls 2 inches apart on parchment paper-lined cookie sheets.
Bake at 350°F for 12 to 16 minutes. Cool on cookie sheets for 5 minutes, then transfer to wire cooling racks.