In a bowl, combine rolled oats, almond milk, maple syrup, cocoa powder, and vanilla extract. Stir until well mixed.
If using, fold in dark chocolate chips for an extra treat. Cover the bowl with plastic wrap and let it sit in the refrigerator for at least 30 minutes or overnight for a thicker consistency.
In another bowl, mix Greek yogurt with honey or maple syrup to sweeten it to your preference.
To assemble, layer the oats mixture and sweetened yogurt in serving glasses or bowls. Start with a layer of oats, then add a layer of yogurt, followed by a layer of mixed berries.
Repeat the layers until the glasses are filled, finishing with a topping of granola and a sprinkle of berries for garnish.
Serve immediately or refrigerate for up to 2 hours before serving. Enjoy!