Spoon the full-fat Greek yogurt into a deep bowl. Deliberately choose the full-fat version, as the healthy fats help keep your blood sugar stable and provide longer satiety.
Chop the walnuts roughly with a knife so you get both larger pieces and some crumbs. Sprinkle them along with the ground flaxseed over the yogurt.
Sprinkle the whole thing with cinnamon and distribute the fresh raspberries over it. Just before eating, stir everything together loosely so the flavors mingle but the walnuts stay crispy.