Combine golden flaxmeal and hot water; stir until a slurry forms. Set aside.
Combine flour, baking powder, baking soda, and salt in a medium bowl.
Cream butter and sugar in a large bowl with an electric mixer. Add dark brown sugar and beat until well-combined. Add egg yolks, egg and flaxmeal slurry; beat until well-combined.
Add flour mixture; beat until well-combined. Stir in chopped chocolate and candy canes. Add half of Peppermint Marshmallow Creme to cookie dough and gently swirl. Cover and chill dough and remaining Marshmallow Creme overnight.
Preheat oven to 375°.
Drop dough by rounded tablespoonfuls onto a parchment-lined baking sheet, about 3 inches apart. Make a small indentation into tops of cookie dough. Add a small amount of excess Peppermint Marshmallow Creme to indentation and swirl slightly into cookie dough.
Bake at 375° for 12 minutes or until edges are golden. Allow to cool slightly before removing to wire racks to cool completely.