Grease an 8x8 square pan with coconut oil.
To make the chocolate layers, add the cacao, coconut oil, and maple syrup to a small pan over low heat. If possible, it's best to use a double boiler to avoid burning the chocolate. Stir constantly until the mixture is completely melted and smooth.
Pour approximately 2/3's of the chocolate mixture into the bottom of the greased pan and reserve the other 1/3. Pop the pan into the freezer for 15 minutes to set.
While the first layer of chocolate is setting, make the caramel by adding the almond butter, maple syrup, coconut oil, vanilla extract, and sea salt to a small sauce pan over medium-low heat. Whisk together constantly for 3-5 minutes or until melted. Let the mixture cool slightly.
Pour about 2/3's of the caramel over the chocolate and carefully spread across (ensure the caramel isn't hot when you pour it over or it will melt the chocolate). You can pour the entire batch of caramel over the chocolate if you want thicker squares, but I usually opt to refrigerate the leftover caramel for later.
Return the pan to the freezer to set the caramel layer for 15-20 minutes.
Pour the remaining chocolate mixture over top, carefully smooth out, and sprinkle with large-flake sea salt (optional).
Return the pan to the freezer to set for 30 minutes.
Carefully turn the pan over to release the chocolate-caramel bar onto a cutting board. Slice into squares and store in refrigerator or freezer.