Preheat the oven to 350°F (177°C) and line a small baking sheet or plate with parchment paper.
Brew and prepare the coffee to your liking.
Prep all ingredients per the instructions above.
In a bowl, mix the ground flaxseed and warm water. Let sit for 5 minutes to thicken.
In a bowl, whisk together the rolled oats, all-purpose flour, almond flour, baking powder, baking soda, cinnamon, and sea salt.
Add the flax mixture, almond butter, coconut oil, maple syrup, and vanilla extract to the dry ingredients. Stir until combined. Fold in the walnuts, blueberries, and lemon zest.
Scoop the dough into an even amount of cookies onto the baking sheet and gently flatten slightly. Bake for 12–14 minutes, or until lightly golden around the edges.
While the cookies bake, add the mango, pineapple, vanilla protein powder, and coconut water to a blender. Blend until smooth and creamy, adding more liquid as needed for desired consistency.
Serve the smoothies with oatmeal breakfast cookies and coffee.