Put the chia seeds with the coconut milk and vanilla extract in a bowl or mason jar and stir well. Wait five minutes and stir again so the seeds don't clump together.
Cover the pudding and refrigerate for at least a couple of hours or overnight. During this time, the chia seeds will swell into a creamy, pudding-like texture.
Stir the pudding once more before serving. Toast the sliced almonds briefly in a dry pan until fragrant and golden brown. Spoon the raspberries onto the pudding and scatter the almonds on top for a crispy contrast.