Place dark chocolate and 1 ¼ cup milk in a small saucepan over medium heat. Stir until chocolate is completely melted and mixture is smooth. Remove from heat and allow to cool for 10 minutes.
Once cooled, stir in 3 tablespoons of chia seeds. Transfer to a bowl and cover in plastic wrap. Place in the refrigerator overnight (or 8 hours) to allow the chia seeds to soften and mixture to thicken.
In a small food processor, add raspberries, maple syrup, and remaining 1 cup milk. Pulse until mixture is smooth.
Pour raspberry mixture into a bowl. Add in remaining 3 tablespoons chia seeds and stir to incorporate. Cover bowl with plastic wrap and place in the refrigerator overnight (or 8 hours) to allow the chia seeds to soften and mixture to thicken.
After both the chocolate and raspberry puddings have chilled, remove from fridge and layer the puddings in a glass container. Garnish with dark chocolate shavings and raspberries.
Keep in the fridge until ready to serve. Consume within 2 days.