Preheat your oven to 160 Fan / 180 C / 350 F / Gas 4 and line a 7 x 9 inch ( 18 x 23 cm) baking tin with parchment paper, covering the base and sides
Melt the coconut oil in a small saucepan or in the microwave and set aside to cool
In a small bowl or mug mix the ground flax seeds with 1/3 cup (80ml) cold water and set that to one side too
In a large bowl put the flour, ginger, nutmeg, baking powder and baking soda
If your crystalised ginger is in largeish chunks, cut into smaller pieces and add that to the large bowl
Peel the bananas and break into chunks into a smaller bowl. Mash with a fork or potato masher - you want them to be well mashed to a puree
Add the coconut sugar, almond milk, cider vinegar, treacle, flax seed mixture and melted oil and whisk together very well
Pour this into the large bowl of dry ingredients and mix everything together with a rubber spatula, scraping up from the bottom of the bowl, making sure no pockets of flour remain
Pour into your baking tin and cook for 45-50 minutes until a toothpick inserted in the center comes out clean
Leave to cool in the tin for 10-15 minutes then carefully lift out onto a cooling rack
Once the cake is completely cooled mix together the icing sugar and water to a runny paste. If it's too thin add a little more icing sugar, too thick add a little more water. When adding, less is definitely more, just add tiny increments at a time to get the right consistency. You want a paste that will drizzle but not one so liquid it doesn't hold its shape and just pools on the top of your cake!
When you're happy with the icing simply use a teaspoon and drizzle/flick/splatter all over the top of the cake. Then sprinkle the pieces of crystalised ginger to top
Leave the icing to set for a few minutes before slicing the cake into 16 squares (or less squares if you want larger portions for dessert!)
Store in an airtight container
Recipe by The Cook & Him at https://thecookandhim.com/recipes/ginger-cake/