1-Gathering and Mixing the Ingredients: Starting with fresh ingredients sets the stage for amazing thumbprint cookies. Begin by placing the butter in a bowl and beating it until it’s creamy this helps create that soft texture we all love. Once creamy, scrape the sides of the bowl and add both sugars, then beat on medium-high speed for 30 to 60 seconds until everything mixes well, forming a smooth base for your dough.

2-Gathering and Mixing the Ingredients: Next, add the egg yolk and vanilla extract, beating them in thoroughly to enhance the flavor. In a separate bowl, whisk together the flour, cornstarch, and salt to ensure even distribution. Gradually mix this dry blend into your wet ingredients on low speed, scraping the sides as needed the dough might feel dry and crumbly, so don’t hesitate to use your hands to finish combining it.

3-Shaping and Chilling the Dough: Once your dough is ready, scoop it into 1 tablespoon-sized balls and roll them until they’re smooth with no cracks this step keeps your cookies looking neat. If you choose, roll the balls in the optional sugar for a sweet coating, then place them on a wax paper-covered plate or cookie sheet. Use your thumb or the back of a teaspoon to gently press an indent in the center of each ball, creating the perfect spot for the jam.

4-Shaping and Chilling the Dough: Chill the dough balls in the freezer for 30 minutes; this step is crucial to prevent spreading and helps maintain the cookie’s shape. While the dough chills, preheat your oven to 375°F (190°C) and prepare your jam by heating it briefly in the microwave for 5 to 10 seconds just enough to soften it without making it hot. Fill each indent to the brim with the jam, and place the cookies at least 2 inches apart on a parchment-lined baking sheet.

5-Baking and Cooling: Bake the cookies for 11 minutes or until the edges turn golden, filling your kitchen with that wonderful aroma. Let them cool completely on the baking sheet before serving to set the jam and keep the cookies firm. This recipe takes about 20 minutes for prep, 30 minutes chilling, and 11 minutes cooking, totaling around 1 hour and 1 minute, and it yields approximately 24 cookies plenty to share or enjoy over the week.