Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a large mixing bowl, whisk together the flour, sugar, cocoa powder, baking powder, and salt.
In another bowl, beat the eggs and vanilla extract. Dissolve the coffee granules in a tablespoon of hot water and add to the egg mixture.
Gradually add the wet ingredients to the dry ingredients, mixing until combined. Stir in the chocolate chips.
Divide the dough in half and shape each half into a log about 12 inches long. Place the logs on the prepared baking sheet and flatten them slightly.
Bake for 25-30 minutes, or until the logs are firm to the touch. Remove from the oven and let cool for 10 minutes.
Using a sharp knife, cut the logs into ½-inch slices. Place the slices cut side down on the baking sheet.
Bake for an additional 10 minutes, then flip the biscotti and bake for another 10 minutes, or until crisp.
Transfer to a wire rack to cool completely before serving.