Preheat your oven to 350°F and line a 9x13 inch baking dish with parchment paper for easy removal. While the oven heats, soak the pitted dates in warm water for 5 minutes to soften them, then drain well—this ensures they'll blend smoothly into the batter and add natural sweetness. Measure out all your wet ingredients (olive oil, almond butter, maple syrup, eggs, and vanilla extract) and have them ready to combine.
Trim the ends off the zucchini and cut into 1-inch chunks. You'll use half the zucchini in the blending step and reserve the other half for texture in the final batter. In a separate bowl, whisk together the oats, baking soda, salt, and cinnamon—I like to do this while waiting for the oven to preheat since these dry ingredients are quick to measure and combine.
Add the wet ingredients from Step 1 along with half of the zucchini chunks (about 1 zucchini's worth) to a blender or food processor. Blend until smooth and well combined—the zucchini will break down completely and add moisture to the batter without being noticeable. Pour this blended mixture into a large mixing bowl.
Add the dry ingredient mixture from Step 2 to the blended wet mixture and stir until just combined—don't overmix. Fold in the remaining zucchini chunks and the chocolate chips with a spatula. I find folding by hand at this stage keeps the bars tender by avoiding overworking the batter, and it also ensures the chocolate chips and zucchini chunks are evenly distributed throughout.
Pour the batter into your prepared 9x13 inch baking dish and spread evenly. Bake for 30-40 minutes until a toothpick inserted into the center comes out clean or with just a few moist crumbs—the bars will continue to set slightly as they cool. The edges should be lightly golden and spring back when gently touched.
Remove the baking dish from the oven and let the bars cool completely in the dish—this usually takes about 1-2 hours at room temperature. Once completely cooled, lift the bars out using the parchment paper overhang and cut into squares. Store in an airtight container for up to 5 days.