Line two baking sheet pan with parchment paper or a silicone liner, set aside.
In a medium-sized mixing bowl, whisk together all-purpose flour, unsweetened cocoa powder, baking soda, and kosher salt. Set aside.
In the bowl of an electric mixer, add butter, granulated sugar, and brown sugar. Mix on medium-speed until light in color and fluffy, 3 minutes.
Add the egg and vanilla extract and conintue mixing on medium speed for 3 minutes. The mixture will be appear fluffy in texture.
Add in the flour mixture, and mix for 2 minutes or until fully combined.
Scoop out 1 teaspoon sized balls and roll into balls and place, 2 inches apart, onto the prepared baking sheet pans. You should 24 balls.
Add the rolled cookies to the fridge and chill for 30 minutes.
When you're ready to bake you cookies, preheat your oven to 350 degrees F.
Once preheated, add a tray of your cookies and bake for 8 minutes.
Remove from the oven and immedaitly press a Hershey kiss gently into the middle of the cookie
Let the cookies fully cool and store in an airtight container for up to 5 days.