Preheat your oven to 350°F (175°C) to ensure even baking.

In a large bowl, combine softened butter and granulated sugar, creaming them together until light and fluffy.

Add the egg and vanilla extract to the mixture, beating until well combined.

In a separate bowl, sift together cocoa powder, flour, baking soda, and salt. Gradually incorporate this dry mixture into the wet ingredients, mixing on low speed.

Using a cookie scoop or spoon, form small balls of dough and place them on a greased or parchment-lined baking sheet, spacing them at least two inches apart.

Bake the cookies for 10-12 minutes, until the edges are firm but the centers remain slightly soft.

Remove from the oven and press a chocolate kiss gently into the center of each cookie. Allow to cool on the baking sheet before transferring to a wire rack.

Enjoy with a glass of milk or share with family and friends!