01 - 
                Whisk together flour, cornstarch, baking powder, and salt. Set aside.
              
              
              
                02 - 
                Cream butter and sugar together with an electric mixer for 4 minutes. Add egg and stir.
              
              
              
                03 - 
                Add remaining cookie dough ingredients and stir until uniform in color. Cover and refrigerate for 2 hours.
              
              
              
                04 - 
                Preheat oven to 350˚F. Roll dough into balls 1 inch across. Roll each ball into a rope of dough about 4 to 5 inches long. Form each rope into a lowercase 'b' shape, then bring the long tail through the hole. Gently pat together to ensure the knots stay secured during baking.
              
              
              
                05 - 
                Place shaped cookies on lined baking sheets. Bake on the center rack for 15 minutes.
              
              
              
                06 - 
                While cookies bake, whisk together glaze ingredients in a bowl.
              
              
              
                07 - 
                Place baked cookies on a wire rack and drizzle glaze over the tops. Add sprinkles, lemon zest, or turbinado sugar immediately while the glaze is wet. Allow to set completely before serving.