01 - Preheat your oven to 350°F. Line two large baking sheets with parchment paper or silicone baking mats to prevent sticking and ensure easy cleanup.
02 - In a large mixing bowl, beat the softened butter and granulated sugar together with an electric mixer on medium-high speed for 3-4 minutes until the mixture is pale yellow, light, and fluffy. This aeration is crucial for tender cookies.
03 - Add the egg and vanilla extract to the butter mixture. Beat on medium speed for another 1-2 minutes until fully incorporated and the mixture looks smooth and glossy.
04 - In a separate medium bowl, whisk together the all-purpose flour, salt, and baking powder until evenly distributed. This ensures the leavening is mixed uniformly throughout the dough.
05 - Gradually add the dry ingredients to the wet mixture, mixing on low speed just until the flour disappears. Do not overmix—the dough should be soft and slightly sticky. Overmixing will result in tough cookies.
06 - Scoop approximately 1 tablespoon of dough and roll between your palms to form smooth balls. Pour sprinkles or sanding sugar into a shallow bowl and roll each dough ball gently to coat evenly on all sides.
07 - Place the coated dough balls 2 inches apart on the prepared baking sheets. This spacing allows room for the cookies to spread slightly during baking without merging together.
08 - Bake one sheet at a time on the center rack for 8-10 minutes. The cookies are done when the edges are set and lightly golden, but the centers still appear slightly soft. They will continue cooking on the hot pan.
09 - Immediately upon removing from the oven, gently press one chocolate blossom into the center of each warm cookie. The slight indentation should be about 1/4 inch deep. Work quickly while cookies are still warm and pliable.
10 - Let the cookies rest on the baking sheet for 5 minutes to set. Using a spatula, carefully transfer them to a wire cooling rack to cool completely for at least 20 minutes before serving or storing.