Line an 8x8-inch square baking pan with parchment paper, leaving a 1–2 inch overhang on two opposite sides to lift the bars out later.
In the bowl of a food processor combine 1/2 cup raw almonds, 1 cup unsweetened flaked coconut, 12 pitted medjool dates, and 2 teaspoons vanilla. Pulse in short bursts until the mixture is finely chopped but still a bit chunky (not a smooth paste).
Add 1/4 cup coconut oil to the processor and pulse just until the mixture holds together when pressed between your fingers. Avoid overprocessing.
Press this base mixture evenly into the prepared pan using your fingers or the bottom of a measuring cup. Smooth and compact it well. Place the pan in the freezer while you make the coconut layer.
In the same food processor (no need to wash it) combine 2 cups unsweetened flaked coconut, 1/2 cup canned coconut milk, 2 tablespoons honey, and a pinch of salt. Pulse until the mixture is evenly ground and holds together when pressed.
Remove the pan from the freezer and press the coconut layer evenly over the almond-date base. Return the pan to the freezer and chill until the coconut layer is firm enough to hold its shape (about 15–30 minutes).
Melt 12 ounces chopped dark or semi-sweet chocolate either over a double boiler or in the microwave in 30-second intervals, stirring between intervals, until smooth.
Remove the pan from the freezer and immediately pour and spread the melted chocolate evenly over the frozen coconut layer.
Drop 2 tablespoons rounded almond butter in small spoonfuls over the melted chocolate. Use a knife or skewer to swirl the almond butter into the chocolate to create a marbled effect. Sprinkle cacao nibs and hemp seeds on top if desired.
Cover the pan and refrigerate for 30 minutes to 1 hour, or until the chocolate is fully set.
Lift the set slab from the pan using the parchment overhang and place on a cutting board. Run a sharp knife briefly under hot water, dry it, and cut the slab into about 16 squares, wiping and reheating the knife between cuts if needed. If the chocolate layer separates from the coconut layer while cutting, press it back into place.
Store the bars in a sealed container in the refrigerator.