Add the frozen cherries to a pot over medium heat. Cook until the cherries release their juice.
Add cinnamon and maple syrup. Cook for 3-5 minutes until the cherries soften.
In a small bowl, mix the arrowroot starch and 1 tsp of water. Then pour the mixture into the cooked cherries. Stir and cook for another 2 minutes until it thickens up.
Turn off the heat and stir in the cherry jam and vanilla extract. Let it chill.
To make the Chocolate Icing
In a food processor, add the avocado, coconut milk, salt, and maple syrup. Blend all together. Stop and scrape down the sides as needed.
Use a double boiler to melt the chocolate. Then pour the melted chocolate into the avocado-coconut mixture in the food processor. Blend to bring all together. Covered and store it in the fridge.
To make the Chocolate Cake
Preheat oven to 180°C / 350°F. Grease two 6" cake tins and line the bottoms with parchment paper. Set them aside.
Add 45 g roasted hazelnuts and 15 g spelt flour to a grinder or a small food processor. Grind them into fine flour. Save the rest hazelnuts for decoration.
In a bowl, add the cocoa powder and the boiling water. Mix to combine.
In another bowl, add the ground hazelnut flour, spelt flour, baking soda, baking powder, ground flaxseed, and salt. Give it a mix.
In a food processor, add the pitted dates, water, and maple syrup. Blitz to make a sweet date paste. Then add the melted coconut oil, apple cider vinegar, and vanilla extract. Mix to combine.
Add the date mixture to the cocoa-water mixture. Mix to incorporate. Then add the flour mixture. Mix just until no clumps remain.
Divide the batter into the prepared cake tins. Gently drop the pans against the counter to remove air bubbles.
Bake for 35-40 minutes until a toothpick inserted in comes out clean. Place the tins on a wire rack to cool down for at least 15 minutes.
Assemble
Remove the cake from the tin and remove the parchment circle of one cake.
Spread about 120ml (1/2 cup) chocolate icing on the cake. Top with cherry filling and spread out evenly. leave about 1.2cm (1/2 inch) space from the edges to prevent spilling out.
Flip the cake upside down to get a flat top and place it on the first layer of the cake. You can also use a knife to chop up the pop-up area if you prefer.
Ice the top and sides of the cake with the remaining chocolate icing.
Crash the left roasted hazelnuts to garnish the cake. Enjoy!