Measure and prep: weigh 80 g rolled oats, chop 20 g walnuts, measure 2 tbsp chia seeds and 2 tbsp (≈32 g) almond butter, slice the bananas. Having everything ready ensures even distribution of flavor and speeds assembly.

Toast the walnuts (optional but recommended): heat a small dry skillet over medium for about 2–3 minutes, add the chopped walnuts and stir constantly until fragrant and slightly darker — 30–60 seconds. Cooling them intensifies their aroma and adds a toasty crunch that contrasts the creamy oats.

Mix the wet base: in a bowl or measuring jug combine 300 ml unsweetened almond milk, 1/2 tsp vanilla extract, a pinch of salt and 1/4–1/2 tsp ground cinnamon. Whisk briefly. The salt and vanilla amplify sweetness; whisking helps distribute the cinnamon evenly so it doesn't clump.

Combine oats, chia and almond butter: in a medium bowl stir together the 80 g rolled oats and 2 tbsp chia seeds. Warm the almond butter for 10–15 seconds in the microwave (or whisk with a tablespoon of warm water) so it loosens — this makes it easier to combine with the milk and prevents clumping. Add the warmed almond butter to the dry mix and stir to coat the oats; coating helps the oats hydrate evenly and embeds the almond flavor throughout.

Bring it together: pour the almond milk mixture over the oat-chia-almond butter mix and stir thoroughly for 20–30 seconds, scraping the bottom. Stirring activates the chia to begin absorbing liquid and ensures every particle of oat is moistened for consistent texture after soaking.

Sweeten and portion: taste the mixture and add 1–2 tsp honey or maple syrup if you prefer sweeter oats. Divide the mixture between two jars or bowls. If you like a pretty presentation and to prevent banana from oxidizing, reserve half the sliced banana for topping and place the other half between layers or sliced into the base.

Assemble and chill: top each jar with banana slices (some inside if you layered), a drizzle of extra almond butter (for sheen and flavor) and the toasted walnuts. Seal the jars or cover bowls and refrigerate for at least 6–8 hours — overnight is ideal. Chilling allows the oats and chia to swell and create a creamy, spoonable texture without cooking.

Finish and serve: before eating, stir gently to reincorporate any separated liquid and adjust thickness with a splash of almond milk if you prefer looser oats. Add an extra pinch of cinnamon and a few walnut pieces on top for texture. Warm a spoonful of almond butter and drizzle across the top for a glossy, restaurant-style finish.