In a large bowl, whisk together the flour, cocoa powder, baking powder, baking soda, and salt until evenly combined. Set this mixture aside.

In the bowl of a standing mixer, add the softened butter and granulated sugar. Beat on medium-high speed for about 3 minutes until the mixture becomes light and fluffy.

Scrape down the sides of the bowl, then add in the eggs one at a time, mixing well after each addition. Finally, stir in the vanilla extract to bring everything together.

With the mixer on low speed, gradually add the dry flour mixture until just combined. Be careful not to overmix; stop as soon as you see no flour streaks.

Roll the dough between sheets of parchment paper to about 1/4-inch thickness. Chill the rolled dough in the fridge for about an hour.

Preheat your oven to 375ºF (190ºC). After chilling, cut the dough into heart shapes using your favorite cookie cutter.

Pop them in the freezer for 10 minutes before baking.

Transfer the chilled cookies to a parchment-lined baking sheet, leaving about 2 inches of space between them. Bake for about 6-8 minutes until they are slightly puffed and starting to crack around the edges.

Let the cookies cool on wire racks for at least 10 minutes before icing.