• In a high-speed blender, add banana, almond milk, peanut butter, apple cider vinegar, vanilla extract, oats, baking powder, baking soda, cinnamon, and salt. Add coconut sugar too if you want to sweeten the batter.
• Blend on the high-speed setting using the blender tamper attachment to push down the oat to the blade. Stop after 30-45 seconds or until the batter is smooth and slightly runny.
• Fold in the chopped nuts and stir with a silicone spatula.
• Rest batter in the blender jug for 10 minutes at room temperature - it will slightly thicken.
• Meanwhile preheat the oven to 350°F (180°C). Line a 12-hole muffin tray with muffin paper liner. Spray some oil on the paper. Set aside.
• Fill each muffin hole with 1/4 cup of batter.
• Bake in the center rack of the oven for about 25 minutes, or until the muffins are golden brown and a toothpick inserted in the center comes out clean or with a little crumb on it.
• Cool down on a wire rack for 30 minutes, add a few chocolate chips if desired, so they melt during the cooling process.

Serving

• Serve with 1 teaspoon peanut butter on top.
• Store in a sealed box in the fridge for up to 4 days or freeze in zip-lock bags for up to 3 months. Thaw at room temperature the day before.