Line the slow cooker with parchment paper, leaving some overhang on the sides for easy removal.
Shred the zucchini and place it in a clean kitchen towel or cheesecloth, then squeeze out as much moisture as possible.
In a large mixing bowl, beat the eggs, melted coconut oil, and vanilla extract together.
Add the squeezed zucchini to the wet ingredients and mix well.
In another bowl, combine the cocoa powder, almond flour, sugar-free sweetener, baking powder, baking soda, and salt.
Fold the dry ingredients into the wet mixture until just combined, then stir in the chocolate chips.
Pour the batter into the prepared slow cooker and spread evenly.
Cover and cook on low for 2.5 hours, or until a toothpick inserted in the center comes out with just a few moist crumbs.
Allow to cool for 15 minutes before using the parchment overhang to lift the cake out of the slow cooker.