In a small saucepan, combine blackberries, maple syrup (if using), and lemon juice. Bring to a gentle simmer over medium-low heat, stirring occasionally, for about 5 minutes until berries soften and release their juices. Mash slightly with a spoon if desired. Remove from heat and let cool completely.

In a medium mixing bowl, whisk together the unsweetened almond milk, protein powder, ground flaxseed, vanilla extract, and salt until smooth and well combined. If using, add additional maple syrup or stevia to sweeten further according to your preference.

Gradually whisk in the chia seeds. Continue whisking for 1-2 minutes to ensure no clumps form and the seeds are evenly dispersed in the liquid.

Cover the bowl tightly or divide the mixture immediately into two small jars. Refrigerate for at least 4 hours, or preferably overnight, until the pudding has thickened to a creamy, gelatinous consistency. For best results, stir halfway through the chilling time if possible for an even creamier texture.

Once the chia pudding is thick, spoon half of it into each serving jar or glass. Layer with a portion of the cooled blackberry compote. Top with the remaining chia pudding.

Garnish with fresh blackberries, chopped nuts, or shredded coconut if desired. Serve chilled for a refreshing and satisfying meal.