Start by pouring the egg yolks into a large bowl and add the powdered sugar. Mix with a hand whisk until the mixture becomes light and creamy: this step helps achieve more crumbly cookies.

Slowly add the peanut oil, continuing to mix to incorporate it well and create a smooth emulsion.
In another bowl, sift the flour, unsweetened cocoa powder, and baking powder. Gradually add the dry ingredients to the liquid mixture, first mixing with a spatula and then with your hands, just until you obtain a soft and homogeneous dough.
Form a dough ball, wrap it in plastic wrap, and let it rest in the refrigerator for at least 30 minutes: the rest makes the shortbread easier to roll out and helps it hold its shape during baking.
After the resting time, roll the dough out on a lightly floured surface to a thickness of about 1/8-3/16 inches. Cut out the heart cookies with the cutters and place them on a baking sheet lined with parchment paper, well spaced apart.
Bake in a preheated static oven at 340°F for 12-15 minutes. In air fryer mode at 320°F for 8-10 minutes

The cookies should still be slightly soft in the center: they will harden as they cool. Once baked, let them cool completely on a wire rack before serving or storing. Sprinkle with more powdered sugar