Melt the baking bar in a small pan over low heat, stirring constantly. Set aside.: As the bar softens you will notice a gentle milky aroma and a smooth, velvety texture forming, which signals that the fat is emulsifying properly. Stirring constantly prevents hot spots and keeps the mixture glossy; if you walk away it can scorch quickly, creating a bitter note. A common mistake is using too high heat, which can separate the fat and leave you with a grainy texture, so keep the flame low and be patient. If the mixture looks slightly separated, remove from heat and whisk steadily until smooth, which usually brings it back together. I like to transfer it to a cool bowl to stop cooking and to protect the egg you add later from accidental warming.
In a small bowl, stir the flour, baking soda and 1/4 teaspoon salt.: When you mix these dry elements you should see a uniform, pale powder, and the salt will dissolve into the flour slightly as you stir. This step ensures even distribution so every bite rises and seasons consistently. If you skip it you risk pockets of baking soda causing uneven puffing. Sifting can help if your flour is clumpy, and measuring accurately keeps the final texture balanced. Avoid overworking the flour now, because it can activate gluten and lead to tougher cookies later.
In a separate small bowl, beat the butter with an electric mixer at medium speed for 30 seconds. Add 1 cup sugar and beat until well combined. Beat in the melted baking bar, egg, buttermilk, and vanilla. Add the flour mixture; beat until well mixed. Cover, chill dough at least one hour, or until easy to handle.: You will hear a soft whirr as the butter and sugar come together into a creamy blend, and the mixture will lighten slightly in color. After adding the warm melted bar, the batter takes on a silky sheen, and the egg helps bind the elements into a cohesive dough. Chilling is crucial for texture control, it firms the fats and prevents excessive spreading in the oven; without chilling the cookies can flatten out and lose their crinkle charm. A common pitfall is not chilling long enough, which leads to thin, greasy cookies, so aim for at least one hour. If the dough becomes too stiff after chilling, let it relax for a few minutes to scoop easily.
Preheat the oven to 375 degrees F.: As the oven warms you may catch a faint toasty smell from the heat elements, which is a cue that the baking environment is stabilizing. A properly preheated oven ensures the cookies begin to set immediately, producing the desired base and slight rise. Placing unchilled dough into a cold oven will result in uneven spread and longer bake times, so wait until it reaches the full temperature. Use an oven thermometer if you suspect your oven runs hot or cool, which helps avoid overbaking or underbaking. A frequent error is guessing the temperature, so allow the oven sufficient time to reach 375 degrees F before baking.
Shape the dough into 1 inch balls; roll in additional sugar. Place 2-inches apart on an ungreased cookie sheet. Bake for 10 minutes, or until bottoms are light brown. Remove and cool on wire rack.: When you roll the chilled dough into balls you should feel a cool, slightly tender texture that retains its shape; coating in extra sugar gives a sparkling exterior and a slight crispness at the edges. Space the balls well because they will spread slightly and need room to develop a rounded base. While baking listen for a faint crackle as edges set, and watch for the bottoms to take on a light golden hue, which means they are done; the tops may still look soft but they set as they cool. Overbaking will produce dry cookies, so err on the side of slightly underbaked if uncertain. A common mistake is crowding the pan, which leads to merged cookies and uneven baking, so leave adequate gaps.
Meanwhile, in saucepan, cook and stir chocolate chips and shortening over low heat until melted. Drizzle over cookies and sprinkle with crushed candy.: As the chocolate chips and shortening melt together they form a glossy, pourable sauce with a warm, rich scent that complements the mint of the candy canes . Drizzling while the chocolate is still warm helps it adhere and creates an appealing contrast against the pale cookie. Immediately sprinkle the crushed candy canes so they stick into the chocolate before it sets; this also preserves the bright red flecks. If the chocolate stiffens too quickly, return the pan to very low heat or microwave in short bursts, stirring between intervals to restore fluidity. A common misstep is applying the candy too late, after the chocolate has set, which prevents proper adhesion and results in fallen pieces.