1. Prepare Your Baking Sheet: Line a large baking sheet (approximately 9×13 inches or similar size) with parchment paper. This is crucial for easy removal of the frozen bark. Make sure the parchment paper extends slightly over the edges to create “handles” for lifting.

2. Combine Yogurt and Sweetener: In a medium-sized bowl, combine the plain Greek yogurt, honey (or maple syrup), and vanilla extract. Stir well with a spoon or whisk until all ingredients are thoroughly mixed and the sweetener is evenly distributed. Taste and adjust sweetness if desired.

3. Spread the Yogurt Mixture: Pour the sweetened yogurt mixture onto the prepared parchment-lined baking sheet. Use an offset spatula or the back of a spoon to spread the yogurt evenly into a layer about 1/4 to 1/2 inch thick. Try to make the layer as consistent as possible for even freezing.

4. Arrange the Berries: Gently scatter the fresh blueberries and raspberries over the top of the yogurt layer. You can create a patriotic pattern with alternating rows of red and blue, or simply sprinkle them randomly for a colorful mosaic.

5. Add Optional Toppings: If using, sprinkle the shredded unsweetened coconut evenly over the berries and yogurt. This adds an extra layer of flavor and texture.

6. Freeze Until Solid: Carefully transfer the baking sheet to the freezer. Ensure it is placed on a flat surface so the yogurt freezes evenly. Freeze for at least 2 to 3 hours, or until the yogurt bark is completely solid and firm to the touch.

7. Break and Serve: Once fully frozen, remove the baking sheet from the freezer. Lift the parchment paper with the frozen bark off the baking sheet. Place it on a cutting board and use your hands to break the bark into irregular pieces of various sizes. You can also use a sharp knife to cut it into more uniform squares or rectangles if preferred. Serve immediately.