Prepare 2 baking sheets by lining them with parchment paper or silicone baking mats. Set aside. Move the oven racks to the upper-middle and lower-middle positions. Turn the oven on to 375°F.
Add 5 ounces silken tofu, ⅔ cup granulated sugar, ¼ cup canola oil, ½ teaspoon instant coffee granules, and 1 teaspoon vanilla to the blender. Blend until smooth and uniform.
Whisk together 1 ½ cups all-purpose flour, ¼ cup cocoa powder, 1 teaspoon baking powder, and ½ teaspoon table salt in a medium bowl. Fold in the tofu mixture and 3 ½ ounces chopped milk or dark chocolate.
Pour about ¼ cup granulated sugar into a small bowl. Using a #40 cookie scoop, portion the dough into 2 Tablespoon portions and roll into balls. Roll the balls in the granulated sugar to coat. Place the sugar-coated dough balls on the prepared baking sheets at least 2 inches apart. Use the palm of your hand or the bottom of a glass to slightly flatten the balls. Repeat with all of the remaining cookie dough.
Bake for 6 minutes, then turn and rotate the pans and cook for an additional 4-6 minutes until the cookies are set. Cool for at least 5 minutes on the baking sheets before serving. These cookies are best served warm (warm for about 10 seconds in the microwave once they've cooled completely).
Store leftover cookies in airtight containers or zipper bags at room temperature for up to 2 days, or in the freezer for an extended period of time. Make sure to cool them completely before transferring to storage containers.