Melt cocoa butter in a double boiler over medium heat, or place in a heat-safe bowl over a tea light. If coconut oil is solid, warm it in a water bath until liquid.
In a bowl, combine cocoa powder, agave syrup, vanilla powder, and sea salt. Pour in the melted cocoa butter and melted coconut oil. Stir for 1-2 minutes until thoroughly combined. Taste and add more agave syrup if desired, keeping in mind the mixture will taste less sweet after cooling.
Line a loaf pan with baking paper or silicone form. Spread a layer of cocoa mixture evenly on the bottom. Arrange the biscuits in a single layer on top. Spread the remaining cocoa mixture over the biscuits until completely covered.
Refrigerate for at least 1 hour until firm. Turn out onto a cutting board, slice, and serve.
Optional: Replace up to 4/5 of the cocoa powder with raw cocoa powder for enhanced health benefits.