Preheat the oven to 350 degrees and line a baking sheet with parchment paper.

In a mixing bowl, stir together the all-purpose flour, almond flour, sugar, baking powder, and salt.

Add the softened butter, egg, and almond extract. Mix until a dough forms.

Work in the green food coloring until the dough reaches a uniform light green shade.

Divide the dough into 8 equal pieces. Roll each piece into a finger shape about 4 inches long and place them on the baking sheet.

Use a knife to press two or three shallow lines across the middle of each finger for knuckle details.

Press one whole almond into the tip of each finger to form the nail.

Bake for 20 minutes, then remove the sheet and let the fingers cool for 10 minutes.

Slice each finger in half crosswise to create shorter biscotti pieces.

Return the pieces to the baking sheet cut side down and bake for another 10 minutes until dry and crisp.