Preheat oven to 325°F (160°C). Line a cookie sheet with parchment paper. Lightly oil the parchment paper with coconut oil. Set aside.
In a large mixing bowl, whisk all the dry ingredients: almond flour, erythritol, psyllium husk, baking powder, salt.
In another bowl, whisk the egg with melted butter, almond extract, and vanilla extract.
Pour the liquid into the dry ingredients bowl, stir to combine well. When the dough is soft and combined, stir in finely chopped almonds and form a dough ball.
Flatten the dough ball onto the prepared cookie sheet to form a flat long cylinder of about 10 inches in length and 1 inch in height (25 cm x 2 cm).
Using a long sharp knife, gently cut the cylinder of dough into 12 biscotti. You can slightly move the knife blade, from left to right, to spread each biscotti from each other. It's great if you can leave a tiny gap between each, they will bake better in the center, making it easier to separate them later on.
Bake for 20-25 minutes or until firm on top and starts to brown.
Remove from the oven, cool down 20 minutes on the cookie sheet (don't touch them, they are still fragile). Then gently turn each biscotti cut-side down onto the cookie sheet
Reduce oven to 300°F (150°C).
Return to the oven for 10-12 minutes until the sides are golden and firm.
Remove from the oven and cool on the cookie sheet completely - about 20 minutes.
Transfer to a cooling rack and wait at least 2 hours to enjoy their full crunchy texture. They harden with time. You can also pop them in the fridge to make them super crunchy.
Decoration - optional
To decorate, melt 1 cup of sugar-free chocolate chips with 1 teaspoon coconut oil. Dip half of each biscotti into the melted chocolate and bring back the decorated biscotti onto a plate covered with parchment paper. Sprinkle chopped nuts coconut on the melted chocolate side. Pop the plate into the freezer for 10 minutes to quickly set the melted chocolate
Store in a cookie jar in the fridge for up to 5 days. Can be frozen in ziplock bags and thaw at room temperature the day before eating.