Preheat oven to 350 F. In a large mixing bowl, whisk together flour, sugar, cocoa powder, cinnamon, baking powder, salt, and almonds. Stir them well until the mixture has a uniform brown color.
In another bowl, whisk together eggs and vanilla. Make a well in the center of the dry ingredients. Pour this mixture into the well. Use a wooden spoon to stir the mixture well until a dry, crumbly dough is formed. Keep stirring until the dough is moistened and clings together when pressed with your fingers.
With the dough still inside the bowl, use your hands to gather the dough together and any loose crumbs. Divide the dough in half. In one compact piece, transfer one half of the dough to the baking pan that is lined with parchment paper. Flour your hands and shape the dough into a log that is 2 inches wide and 1 inch deep. Flour your hands as needed to prevent the dough from sticking. Repeat the process with the other remaining half of the dough, leaving about two inches of space in between the logs.
Bake for 25-30 minutes, or until the logs are set and firm to the touch. The top may have some cracks.
Remove the baking sheet from the oven and slide the logs along with the parchment paper into a cooling rack. Let the logs cool completely.
Preheat oven to 350 F (if you turned it off earlier). Using a sharp, serrated knife, slice the logs diagonally into 1/4 inch thickness. Arrange the slices on a baking sheet (or two). Bake the biscotti for 10-12 minutes or until they are crisp on the edges and slightly soft in the centers. They will crisp up as they cool. Watch closely as they can easily turn from crisp to having burnt edges. Cool the biscotti.
To glaze them, arrange the biscotti close together on a wire rack. Place a baking sheet lined with foil underneath the rack to catch any chocolate drippings. Drizzle the chocolate using a spoon over the biscotti in a sweeping motion from left to right until all the biscotti have chocolate drizzles on them.