To make the cake: Preheat the oven to 170 degrees Celsius. (Note: Double the recipe to make two 8in cakes.) Grease two 8-inch cake pans with butter or vegetable oil, and line the base with baking sheet.
Sift flour, xanthan gum, cocoa, baking powder, baking soda, and salt into a large mixing bowl.
Add brown sugar and white sugar, and mix the dry ingredients well with a whisk.
Add the eggs, coconut milk, oil and vanilla, and beat the mixture until smooth.
Add coffee powder into the boiling water and mix.
Carefully whisk in the hot coffee with the rest of the mixture. This will turn the batter into a thin and runny consistency.
Divide the cake batter evenly between the two 8-inch cake tins. (Tip: Use a large ladle and place one scoop alternately in each cake tin to divide it as evenly as possible)
Bake for 40 minutes, or until a toothpick inserted in the middle of the cake comes out clean. Let it cool in the pans for 5 minutes.
Lay out a large sheet of baking paper on a flat surface (e.g. a large cutting board or the kitchen countertop), then turn out the cake onto the baking sheet upside down, with the top side now facing downwards and let cool completely. This will ensure a flat top on the cake.
To make the filling
Cut strawberries up roughly into even and medium-sized pieces. Leave at least 10 strawberries uncut for garnish.
Place strawberries into a saucepan over medium heat along with the brown sugar, white sugar, and lemon juice, and stir regularly to prevent burning.
Once the strawberries can be mashed easily with the back of a spoon, remove strawberry chunks into a bowl and leave to cool.
Turn up the heat and bring the remaining juices in the saucepan to a boil for about 2-3 minutes, until the sauce has visibly thickened.
Remove from heat and pour out the sauce into the bowl and leave to cool completely.
To make the ganache
Heat up the cream in the microwave for about 20 seconds.
Pour the heated cream onto the chocolate chips and leave for 1 minute.
Stir the mixture until the consistency is even. If all the chocolate chips have not melted, pop into the microwave for 10-15 seconds at a time and stir.
Assembling the cake
Place the first layer of cake on a cake board or on a large and flat plate.
Place all the strawberry chunks (save 5-6 pieces for garnishing) on the cake, and spread them evenly so that none are sticking out too much, and the layer is even in height. Pour the sauce over the chunks.
Place the second layer of cake on top of the strawberries, and push down lightly.
Pour the cooled ganache on top of the cake. Using the back of a spoon, spread the ganache in a circular motion from the centre of the cake spreading outwards.
For garnish, place the 5-6 remaining pieces of strawberry chunks on the centre of the cake, accompanied by a few pieces of chocolate chips.