Combine dry ingredients first by whisking cocoa powder, chia seeds, and salt in a medium bowl, breaking up any cocoa clumps until the mixture is uniform.
Add the wet ingredients by pouring in the milk, maple syrup, and vanilla extract. Whisk vigorously for about 30-60 seconds until everything is well incorporated.
Let the mixture rest for 10 minutes, then whisk again thoroughly. This prevents chia seeds from clumping together at the bottom.
Transfer to serving containers – either portion into individual jars or keep in one larger container. Cover with lids or plastic wrap.
Refrigerate for at least 4 hours, but preferably overnight. The pudding will thicken as the chia seeds absorb the liquid and create a gel-like consistency.
Check the texture before serving – it should be thick and spoonable. If too thick, add a splash more milk; if too thin, stir in another teaspoon of chia seeds and wait 30 minutes.
Top with your favorite garnishes just before serving for added texture, flavor, and visual appeal.