In a bowl, combine flour, salt, and baking powder, whisk and set aside.
In a stand mixer, cream together butter and sugar until light and fluffy, about 2 minutes.
Add in eggs and continue to mix, scraping down the sides occasionally.
Add in vanilla extract and cocoa powder, mixing on low speed until no streaks remain. Scrape down sides to ensure all ingredients are well incorporated.
Add in flour mixture in small increments until all of the mixture is combined.
Shape dough into disc and wrap well in plastic wrap. Refrigerate for at least one hour.
Preheat oven to 350°F and prepare 2 baking sheets with parchment paper or silicone baking mats.
Remove dough from fridge and separate into 4 sections.
On a prepared surface (I "flour" my counter with powdered sugar), roll out the dough to ¼ inch thickness. Cut out the cookies with a heart shaped cookie cutter.
Place the cut-outs on the prepared baking sheets about 1 inch apart. Bake in the oven for 9-10 minutes until the edges are set and center is still soft. Repeat with remaining dough.
Transfer to a rack to cool. Once completely cooled, cookies can be iced.
