Heat the oven to 375°F. Line two baking sheets with parchment paper.
Whisk together the flour, cacoa, baking soda, and baking powder in a large bowl and set aside.
In the bowl of a stand mixer fitted with a paddle attachment, cream the butter and sugars together. Add the wet ingredients one at a time, mixing until each is incorporated.
With the mixer on low, add the dry mixture a half a cup at a time. The final batter will be relatively loose.
Transfer the batter to a piping bag fitted with a large round tip (or just snip the end of your piping bag). Pipe the batter out onto a parchment paper in v-shapes of similar size. As the cake bakes, the shape will expand outward into a heart-shape.
Bake for 8 minutes until the batter rises and is cooked through. Let the cakes cool for 5 minutes, then transfer them to a cooling rack.