Oven Preparation: Initiate by preheating your oven to a temperature of 350° Fahrenheit. Prepare two large cookie sheets by lining them with parchment paper. Set these aside for subsequent use.
Dry Ingredients Mixture: In a medium-sized mixing bowl, combine the following dry ingredients: all-purpose flour, unsweetened cocoa powder, cornstarch, baking powder, and salt. Employ a whisk for thorough mixing, ensuring an even distribution of the ingredients.
Creaming Process: In a separate, larger bowl, utilize an electric hand mixer to cream together the unsalted butter and granulated sugar. Continue this process until the mixture achieves a fluffy consistency.
Incorporation of Egg and Vanilla Extract: To the creamed mixture, add one large egg and a teaspoon of vanilla extract. Continue to mix, ensuring these ingredients are well integrated into the batter.
Combining Wet and Dry Mixtures: Gradually introduce the dry ingredient mixture to the creamed mixture. Mix at a low speed setting until the dough reaches a crumbly yet pliable consistency.
Forming the Cookies: Utilize a 1 1/2 tablespoon cookie scoop to extract portions of dough. Manually roll these portions into tight, smooth balls and place them on the prepared cookie sheets, maintaining a distance of approximately 2 inches between each cookie.
Shaping the Cookies: Gently press down the center of each dough ball using a measuring teaspoon. It is acceptable for minor cracks to appear in the dough during this process.
Baking: Place one cookie sheet in the preheated oven and bake for a duration of 15 minutes, or until the cookies have slightly risen. If necessary, repress the centers of the cookies post-baking if they have risen excessively.
Adding the Peppermint Kisses: After baking, transfer the cookies to a cooling rack. Allow them to cool for approximately 5 minutes, until they are warm but not excessively hot to the touch. Subsequently, press a peppermint kiss candy into the center of each cookie.
Final Cooling: Await the complete cooling of the cookies before serving. This step is crucial to allow the flavors to fully develop and the cookies to achieve the desired texture.