Add the almond milk to a high-speed blender first, followed by the chocolate protein powder, cocoa powder, peanut butter, honey, frozen banana, and ground flaxseed.
Blend on high speed until the shake is completely smooth and creamy, stopping to scrape down the sides of the blender if needed.
If the shake is too thick, add a splash more almond milk and blend again until it reaches your desired consistency.
Pour into a glass and enjoy immediately for the best flavor and texture.