First, whisk together the egg, maple syrup, coconut oil, and vanilla until well mixed. This is best done with a stiff whisk or a hand or stand mixer.
Next, add the almond flour, tapioca flour, and baking soda to the bowl and mix until a large ball of dough forms.
Roll out the dough and cut out heart shapes with a cookie cutter. Then transfer to a baking sheet to bake.
Draw an outline of the heart around the cooled cookie. Be sure to leave about a ½ inch barrier from the edge of the cookie.
Fill in the center of the outline with icing. This is called "flooding".