Preheat oven to 350 degrees and line an 8x8 glass baking dish with aluminum foil then spray foil with olive oil cooking spray.
Add almond milk, spinach, pea protein, chocolate peanut butter powder, and honey to high speed blender and blend until smooth with no traces of the spinach leaves - approximate 20-30 seconds.
Add dates and peanut butter to food processor and process on high for 20 seconds. Stop and scrape sides, then blend another 10 seconds or so.
Add spinach/milk/pea protein mixture from blender to date and peanut butter mixture, then process 15-20 seconds.
Finally, add almond flour and cacao powder and continue blending another 20-30, stopping to scrape down sides as needed. Texture should be a thick, smooth consistency - see photos.
Add batter to greased dish and bake 18-20 minutes or until toothpick inserted around outer section comes out clean. Allow to cool at least 15-20 minutes before cutting and FULLY cool before storing. (I like to bake mine right at 18 minutes, leaving them a little underdone so they're really fudgy!)
Store at room temperature in air tight container for 2-3 days or refrigerate for up to a week. If stored in refrigerator, allow to come to room temperature before serving for optimal gooeyness. Enjoy!