Prepare the Pan: Line a 13x9-inch baking pan with a silicone baking mat or a sheet of parchment paper. Ensure there is a slight overhang on the sides to make lifting the bark easier once frozen.
Zest the Citrus: Finely grate the zest from half a lemon and half an orange. Set aside about one-third of this combined zest to use as a garnish later.
Create the Base: In a medium mixing bowl, whisk the non-fat Greek yogurt briefly with a spatula until it is smooth and free of lumps.
Infuse the Flavors: Pour the maple syrup, lemon juice, orange juice, and almond extract into the yogurt. Add the larger portion of the citrus zest. Stir thoroughly until all ingredients are fully incorporated and the mixture is uniform.
Assemble the Bark: Pour the yogurt mixture into the center of your prepared pan. Use the spatula to spread it into an even layer, approximately ¼-inch thick.
Garnish: Artfully scatter the fresh raspberries and hemp hearts across the surface. Sprinkle the reserved citrus zest evenly over the top for a final pop of color.
Freeze: Carefully place the pan flat in the freezer. Freeze for a minimum of 4 hours, or until the bark is completely solid and snaps easily.
Serve: Use the parchment overhangs to lift the slab from the pan. Break into irregular shards by hand. Serve immediately.