Measure and combine the dry base: In a medium mixing bowl or a 1‑quart (1L) jar, add 1 cup (90 g) rolled oats and 2 tbsp (24 g) chia seeds. Mixing the chia with the oats before adding liquid helps them hydrate evenly and prevents clumping; the chia will thicken the mixture overnight, giving a spoonable, almost pudding-like texture.

Add the spices and salt: Sprinkle 1 tsp ground cinnamon and a pinch of fine sea salt over the oats. Salt brightens and balances the sweetness; cinnamon adds warm aroma and depth that pairs beautifully with almond and banana.

Stir in the wet ingredients: Pour 1 1/2 cups (360 ml) unsweetened almond milk and 1/2 tsp vanilla extract into the bowl. Use a fork or small whisk to combine, breaking up any clumps. A little whisking helps the oats start absorbing liquid evenly and distributes the vanilla/cinnamon so you get consistent flavor.

Sweeten and fold in almond butter: If using, stir in 1 tbsp maple syrup now so it dissolves into the liquid. Add 3 tbsp (48 g) almond butter — for a smooth finish, spoon the almond butter into the bowl and use the back of a spoon to vigorously swirl it into the oat mixture until it becomes streaky and partly incorporated. This gives pockets of nutty creaminess and helps the oats set with richer mouthfeel.

Add banana and pre-mix (optional): Reserve a few slices for topping (about 6–8 slices). Chop or mash the remaining banana and stir it into the oat mixture. Mashing some banana into the mix adds natural sweetness and helps the oats thicken as it releases sugars and moisture; leaving some slices whole keeps a fresh textural contrast.

Portion and chill: Transfer the mixture into two serving jars or airtight containers, dividing evenly. Press a layer down lightly with the back of a spoon to remove major air pockets (this encourages even hydration). Seal and refrigerate for at least 6–8 hours, or overnight. Cold refrigeration allows the oats and chia to fully absorb liquid and develop their creamy texture without cooking.

Finish and serve: In the morning, give each jar a good stir. Taste and adjust sweetness (add more maple syrup if desired). Top with the reserved banana slices and a light sprinkle of cinnamon. If you like a contrasting savory note, finish with a tiny pinch of flaky sea salt — it amplifies the almond flavor and balances sweetness.

Optional warm variation: For a warmed version, scoop the contents into a microwave-safe bowl and microwave for 30–45 seconds, then stir and heat another 15–30 seconds until just warm. Warming makes the almond butter more fluid and creates a comforting oatmeal-like texture — but avoid overcooking or the banana can become too soft.