Toast the hazelnuts (if not pre-toasted): Place the 1 tbsp chopped hazelnuts in a dry skillet over medium heat. Shake the pan or stir frequently for 3–4 minutes until they smell nutty and the skins show light browning. Toasting releases the oils and deepens flavor; it also creates a more satisfying crunch against the creamy oats. Transfer to a plate to cool so they stop cooking.

Dice the pear: Trim any stem, then halve the pear and dice half (about 65 g) into 1/4-inch (6 mm) pieces. Keep the skin on for texture and color unless you prefer peeled fruit. Small, even dice ensures pear pieces stay tender and disperse flavor evenly through the oats.

Combine the base: In a 12–16 ounce jar or airtight container, add 1/2 cup (45 g) rolled oats, 1 tbsp chia seeds, and 1/2 tsp ground cinnamon. Add a small pinch of fine sea salt to heighten sweetness and balance the flavors. Salt is a flavor amplifier—it makes the pears and cinnamon taste brighter.

Add liquids and mix: Pour in 3/4 cup (180 ml) milk (or plant milk) and 1/4 tsp vanilla extract if using. Stir vigorously for 20–30 seconds to ensure the chia seeds are evenly distributed and start absorbing liquid; this prevents clumping. Mixing also hydrates the oats' surface so they soften uniformly overnight.

Fold in fruit and sweetener: Gently fold the diced pear into the oat mixture, reserving a few pieces for the top if you like. If you want a touch of extra sweetness, stir in 1 tsp maple syrup now—this balances the natural pear tartness and complements cinnamon. Because maple is optional, taste in the morning and add more if needed.

Seal and chill: Press a piece of plastic wrap directly on the surface (optional) and screw on the lid. Refrigerate at least 6 hours or overnight (6–8 hours). The resting time allows oats and chia to absorb the milk, creating a creamy, pudding-like texture without cooking. Chilling also allows the flavors to meld.

Check and adjust in the morning: Give the oats a stir. If the mixture is thicker than you prefer, stir in 1–2 tbsp additional milk to loosen (liquid is absorbed over time). Taste and adjust sweetness with a little more maple if desired. Textural adjustment here is important—overnight soaking yields a range from spoonable to porridge-thick, so personalize.

Finish and serve: Top with the toasted chopped hazelnuts and the reserved pear dice. If you like a contrast in texture and temperature, warm the hazelnuts for 10 seconds in a skillet or microwave before topping to revive aroma. Serve chilled or at room temperature.

Make-ahead and storage notes: Keep refrigerated up to 3 days in a sealed container. If storing longer, add nuts and fresh fruit only when serving to preserve crunch and color. For travel, use a jar with a tight-fitting lid and include the nuts separately to prevent softening.