Preheat oven to 350F. Line a baking pan with parchment paper.
Make one flaxseed egg: In a small bowl, use a fork to whisk together the ground flaxseed with 3 tablespoons of water. Allow the mixture to sit until thick, about 5-10 minutes.
In a larger bowl, whisk together the oat flour, almond flour, and baking powder. Add in the almond butter, maple syrup, flaxseed egg, vanilla extract, and almond extract. Mix together until all ingredients are evenly incorporated.
Continuously wet your fingers to roll 2 tablespoons of cookie batter into a ball, and then pinch one side to form a teardrop shape. Repeat until all batter is used. Use the almond slices to create 3-5 layers of quills on each hedgehod cookie.
Bake for 10-12 minutes. Allow the cookies to cool for at least 1 hour.
Once the cookies are cooled, melt dark chocolate to create a nose and eyes on each hedgehog cookie.