01 - Line an 8x8-inch baking pan with parchment paper, allowing an overhang on opposite sides for easy removal of the frozen bars.
02 - Combine granola, honey (or maple syrup), and melted coconut oil in a medium bowl. Mix until all ingredients are evenly coated and the mixture holds together when pressed.
03 - Transfer the granola mixture to the prepared pan. Press firmly and evenly across the bottom using the back of a spoon or your hands to create a compact, uniform base layer.
04 - In a separate bowl, whisk together Greek yogurt, honey (or agave syrup), and vanilla extract until completely smooth and well combined.
05 - Spread the yogurt mixture evenly over the granola base using a spatula, ensuring full coverage to the edges.
06 - Distribute mixed berries evenly over the yogurt layer. Sprinkle with chia seeds if using for added texture and nutritional benefits.
07 - Place the pan in the freezer and freeze for at least 4 hours, or until completely firm throughout. For best results, freeze overnight.
08 - Use the parchment paper overhang to lift the frozen slab from the pan. Transfer to a cutting board and let sit for 5-10 minutes at room temperature to soften slightly before cutting into 12 bars with a sharp knife. Store in an airtight container in the freezer and serve frozen or slightly thawed.