1. Preheat your oven to 350°F (175°C). Line a large baking sheet with parchment paper. This prevents sticking and makes for easy cleanup. Set aside.

2. In the bowl of a stand mixer fitted with the paddle attachment (or using a hand mixer), cream together the softened butter, brown sugar, and granulated sugar until the mixture is light, fluffy, and smooth. This typically takes 2-3 minutes. Scrape down the sides of the bowl as needed.

3. Add the egg yolk, vanilla extract, and red food coloring gel to the creamed butter mixture. Mix on medium speed until all ingredients are thoroughly combined and the color is evenly distributed throughout the dough. For a vibrant red, ensure your food coloring gel is potent.

4. In a separate bowl, whisk together the all-purpose flour, cocoa powder, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients in the stand mixer. Mix on low speed, just until the flour mixture disappears and the dough comes together. Be careful not to overmix, as this can lead to tough cookies.

5. Using a tablespoon or a small cookie scoop, portion out 18 equally sized cookie dough balls. Roll each ball smoothly between the palms of your hands to create a uniform shape.

6. Pour the red sanding sugar into a shallow bowl. Roll each cookie dough ball thoroughly in the sanding sugar until it’s completely coated. This adds a beautiful sparkle and a delightful textural crunch to the finished cookies.

7. Place the coated cookie balls onto the prepared baking sheet, leaving about 2 inches between each cookie to allow for spreading. Bake in the preheated oven for 10 minutes. The edges should be set, but the centers will still look soft and slightly puffed.

8. As soon as you pull the cookies out of the oven, immediately place one unwrapped Hershey’s Kiss in the center of each cookie. Gently press down on the Kiss, allowing the warm cookie to slightly envelop its base. The residual heat will soften the chocolate perfectly.

9. Let the cookies cool on the baking sheet for at least 10 minutes. This allows them to set up properly and prevents the Kisses from melting completely or falling off. After 10 minutes, carefully transfer them to a wire cooling rack to cool completely. Once cooled, enjoy your beautiful and delicious Red Velvet Blossom Cookies!