Preheat the Oven: Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper or a silicone baking mat for easy cleanup.
Combine Dry Ingredients: In a medium-sized bowl, whisk together the all-purpose flour, cocoa powder, baking soda, and salt. Set this mixture aside.
Cream Butter and Sugar: In a large bowl, beat the softened butter and granulated sugar together with a hand mixer or stand mixer on medium speed until light and fluffy (about 2-3 minutes).
Add Wet Ingredients: Add the egg, vanilla extract, and red food coloring to the butter-sugar mixture. Mix until everything is combined. Then, add the buttermilk and continue mixing until smooth.
Incorporate Dry Ingredients: Gradually add the dry ingredients to the wet ingredients, mixing on low speed until the dough comes together and is well combined. The dough should be soft and slightly sticky.
Shape the Cookies: Using a cookie scoop or a tablespoon, scoop out dough and roll it into balls. Place the dough balls about 2 inches apart on the prepared baking sheet.
Bake: Bake the cookies in the preheated oven for 8-10 minutes. The cookies will spread slightly and look set at the edges but still soft in the center.
Add Hershey's Kisses: As soon as the cookies come out of the oven, press a Hershey's Kiss (or other chocolate) into the center of each cookie while they are still warm.
Cool: Allow the cookies to cool completely on a wire rack. The chocolate will harden as the cookies cool down.
Serve and Enjoy: Once the cookies have cooled, serve and enjoy these sweet, indulgent Red Velvet Blossom Cookies!