In a small mixing bowl, whisk together the hazelnut butter, maple syrup, cocoa butter, cocoa powder, and vanilla extract. Once fully smooth, cover with plastic film and place in the refrigerator for at least 2 hours, or until firm.

Place the pitted Medjool dates and oat flour in the bowl of a food processor. Process for 10-15 seconds, or until it looks like a smooth paste. Add the almond flour, coconut flour, vanilla extract, and process for another 10 seconds. You should get a soft paste that doesn't stick to your hands. If it's too sticky add more oat or coconut flour and process again.

Add the almonds and process for another 7-10 seconds, or until they are chopped into small pieces. Use your hands to form a large ball with the dough, it should hold together well and be soft. If it appears too dry or crumbly, add 1-2 tablespoons of maple syrup and mix again.

Scoop out about 1/2 tablespoon of dough, form a ball and flatten it into a thin circle with your hands. Place 1 and 1/2 teaspoon of chocolate hazelnut butter in the middle of the circle. Top with another circle of dough and seal the edges with your fingers. Roll into a ball, then place on parchment paper and slightly flatten by pressing with the palm of your hand. Repeat with the remaining dough.

Refrigerate for at least 1 hour before wrapping each cookie in plastic film. Cookies will keep in the refrigerator for up to 3 weeks, or at room temperature for up to 2 weeks. These cookies are firmer straight out of the refrigerator and become slightly softer at room temperature.