Preheat oven to 350°F (175°C).

Line a baking sheet with parchment paper and set aside.

In a large bowl, whisk together the almond flour, cassava flour, and sugar. Add the shortening (or coconut oil) and maple syrup, then stir until a smooth dough forms.

Place the dough between two sheets of parchment paper and roll it out to ¼-inch thickness.

Use a 2.5-inch heart-shaped cookie cutter to cut out 20-22 hearts. Then, use a mini 0.5-inch heart cutter to cut out small heart “windows” in half of the cookies.

Transfer the cookies to the prepared baking sheet and bake for 12-14 minutes, checking at the 10-minute mark to prevent over-browning. Let them cool completely on a wire rack.

Once cooled, spread ½ teaspoon of chocolate hazelnut spread onto each solid heart cookie. Place a “window” heart cookie on top to form a sandwich.

Store in an airtight container at room temperature.