Place about ⅔ of the blackberries in a mason jar (or small bowl). Mash with fork until mostly smooth.
Add the milk, yogurt, oats, maple syrup, lemon zest, and salt to the berries. Mix until well combined.
Top oats with remaining berries, then cover jar (or bowl).
Refrigerate overnight (or at least 4 hours) before eating. Enjoy!
Notes
Milk - Regular milk (such as 2% or whole) and plant based milk (such as almond, oat, coconut, etc.) will both work great for this recipe. I typically use unsweetened soy milk, which has a neutral flavor and thick, creamy texture.Yogurt - Plain yogurt (not Greek) works best for this recipe. If you'd like to use Greek yogurt, I'd recommend thinning it with a tablespoon or two of milk (or water) first, otherwise it will be too thick.Leftover Lemon - The lemon zest really makes the flavor of these oats pop! And you can use the leftover lemon so many ways ... this Single Serving Lemonade and this Lemon Olive Oil Dressing are two of my faves!Multiple Servings - To make multiple servings, line up the jars on your counter, then add the ingredients assembly line-style. Mash the berries, add the oats, then milk, etc. Mix and refrigerate as directed.More Tips + Tricks - Read the info before this recipe card for helpful tips, variations, and related recipes!