Step 1: Preheat your oven to 350°F (175°C). Line baking sheets with parchment paper.
Step 2: In a medium bowl, whisk together the flour, cocoa powder, baking soda, and salt. Set aside.
Step 3: In a large bowl, cream together the softened butter and granulated sugar with an electric mixer until light and fluffy. Beat in the egg and vanilla extract until well combined.
Step 4: In a small bowl, combine the buttermilk and white vinegar. Add the pink gel food coloring to the buttermilk mixture and stir until evenly colored.
Step 5: Gradually add the dry ingredients to the wet ingredients, alternating with the colored buttermilk mixture, beginning and ending with the dry ingredients. Mix on low speed until just combined, being careful not to overmix.
Step 6: (Optional) Cover the dough and chill in the refrigerator for 30 minutes. This helps prevent spreading.
Step 7: Drop rounded tablespoons of dough onto the prepared baking sheets, spacing them about 2 inches apart.
Step 8: Bake for 10-12 minutes, or until the edges are lightly golden and the centers are set. Do not overbake.
Step 9: Let the cookies cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.
Step 10: While the cookies cool, prepare the cream cheese frosting: In a medium bowl, beat the softened cream cheese and butter together until smooth.
Step 11: Gradually add the sifted powdered sugar, beating until smooth and creamy. Stir in the vanilla extract and a pinch of salt.
Step 12: Once the cookies are completely cool, frost each cookie generously with cream cheese frosting. Decorate with festive sprinkles if desired. Serve and enjoy!