Preheat oven to 350°F (175°C). Line baking tray with parchment paper like a baking queen.
Combine flax and water. Let it chill for 5 minutes. It thickens up like good gossip.
In a large bowl, mix flour, almond flour, sugar, baking powder, and salt.
Stir in coconut oil, coffee, vanilla, and the flax egg. Mix until a sticky dough forms.
Shape into a log about 8 inches long, 3 inches wide. Place on tray and press gently.
Bake for 15 minutes. Let it cool for 10. Slice into ½-inch pieces with your sassiest knife.
Lay slices flat and bake again for 15 minutes. Cool completely—yes, patience is a virtue.
For frosting, beat vegan butter until creamy. Add sugar, espresso, milk, and vanilla. Whip until it’s smoother than your ex’s lies.
Frost each biscotti with a generous swipe of cream. Let set. Try not to eat them all immediately.