Take the small frozen banana out of the freezer and break it by hand into a few rough pieces. Wash the generous handful of fresh spinach under cold running water and let the leaves drain well in a colander.
Put the pieces of frozen banana and the drained spinach into the blender pitcher. Add the scoop of collagen peptides, a tablespoon of almond butter and 150ml of unsweetened coconut milk to this. Turn on the blender to high setting and puree everything for about one minute until thick, creamy and completely smooth.
Meanwhile, break the three walnuts into slightly smaller, bite-sized pieces. Pour the thick smoothie directly from the blender into a spacious breakfast bowl and scrape the sides of the blender pitcher clean with a spatula.
Distribute the tablespoon of pumpkin seeds and the chopped walnuts evenly over the top of the green smoothie. Serve the bowl immediately with a spoon, while the contents are still firm and well chilled.