Make the chia jam by heating the berries in a pan, and simmer on low heat for a few minutes. Stir in the chia seeds. Transfer to a heat-proof jar and let it sit for 10-15 minutes.
Meanwhile, in a large bowl, mix the oats, chia seeds, almond flour, Greek yoghurt, milk, lemon zest and juice, maple syrup, protein powder (if using) until smooth.
Layer the oat mix and chia jam into jars, divide equally between. Top with fresh blueberries and optional almond flakes and cashew butter.
Let it set in the fridge for 2 hours or overnight.
