Preheat oven to 350° F (176° C). Line 2 half sheet rimmed baking trays with parchment or silicone mats.

In a large mixing bowl, whisk together all purpose flour, granulated sugar, espresso powder, baking powder, ground cinnamon, and kosher salt.

Add the cubed butter. With your hands, rub together until the mixture resembles coarse breadcrumbs.

Make a well in the dry ingredients. Add the eggs, coffee extract, and vanilla extract and use a bench scraper to combine, working the ingredients together until a soft, sticky dough forms.

Work the chocolate chips into the dough.

On a very generously floured countertop or a silicone rolling mat, divide the dough into 2 equal portions.**

Shape each portion into a log, approximately 8 inches long and about 1 1/2 inches in diameter.

Arrange logs on 1 prepared tray, allowing 5-6 inches of space in between. With a pastry brush, brush both logs with egg white.

Sprinkle generously with Demerara sugar.

Bake in preheated oven for 25 minutes, or until puffy, well-risen and set. Remove from oven and cool 15 minutes on tray.

With a palette knife, lift logs onto a large cutting board. With a serrated knife, cut each log on the diagonal, creating 1-inch wide slices.

Divide slices between both prepared trays. Arrange slices upright and bake for an additional 20 minutes, or until dry to the touch.

Transfer to a wire rack to cool.

Store espresso biscotti in an airtight container for up to 3 days, or freeze for up to 3 months. Thaw at room temperature.