First, prepare your tin. Line a 20cm x 20cm square baking tin with baking parchment, ensuring an overhang on all sides. This will make lifting the set bars out much easier later.

In a large mixing bowl, combine the desiccated coconut, coconut flour, and a pinch of fine sea salt. Give them a good stir with a wooden spoon until everything is evenly distributed. You’ll notice the dry ingredients coming together, ready for the wet components.

In a separate, smaller bowl, gently warm the coconut butter until it’s soft and creamy, almost like a thick paste, but not fully liquid. Whisk in the thick cream from the chilled coconut milk, the sugar-free maple syrup (or liquid erythritol blend), and the vanilla extract. The mixture should become smooth and fragrant, emitting a lovely sweet aroma.

Pour the wet ingredients into the dry coconut mixture. Using a sturdy spatula or your hands, mix thoroughly until a thick, uniform dough forms. The mixture should be sticky enough to hold together when pressed, taking on a slightly clumpy but cohesive texture. If it feels too dry, add a tiny splash more coconut milk; if too wet, a touch more coconut flour.

Press the coconut mixture firmly and evenly into the prepared baking tin. Use the back of a spoon or your clean hands to compact it tightly. This is crucial for the bars to hold their shape, so press down until the surface looks smooth and the base feels solid. Place the tin in the freezer for 15-20 minutes to firm up while you prepare the chocolate topping.

While the base chills, melt the sugar-free dark chocolate and coconut oil together. You can do this in a heatproof bowl set over a saucepan of simmering water (a bain-marie) or in the microwave in 30-second bursts, stirring well after each. Stir until the chocolate is completely smooth, glossy, and has a rich, deep brown colour, with no visible lumps.

Retrieve the chilled coconut base from the freezer. Pour the melted chocolate mixture evenly over the top, spreading it right to the edges with a spatula. If you're adding optional toppings like chopped nuts or orange zest, sprinkle them over the chocolate now, before it sets. The chocolate will look beautifully reflective and smooth.

Return the tin to the refrigerator for at least 1-2 hours, or until the chocolate topping is completely firm to the touch and has lost its glossy sheen, becoming matte. The bars should feel solid and ready to cut.

Once fully set, use the parchment paper overhangs to lift the slab out of the tin. Place it on a cutting board and use a sharp, warm knife to cut into 12-16 bars. The knife will glide through the firm chocolate with a satisfying 'thunk' as it hits the coconut base. For cleaner cuts, wipe the knife between slices.

Store the finished bars in an airtight container in the refrigerator for up to a week. They're also excellent straight from the freezer for a firmer, colder treat.